Slugthrowers

Slugthrowers are projectile weapon firearms, i.e., an ordinary gun that shoots bullets.

First off, let me point out that handgun enthusiasts are quite opinionated, and there are a few points of contentions on the subject. There are some debates that have gone on for decades. For instance, try asking some hunters about the theory of "hydrostatic shock" and you'll get an ear full. So if you are a handgun expert, and you read something in the following that you disagree with, please don't get excited. Just send me an email and we'll try to present your side.

Refer to the weapon energy and weapon range tables to compare energy weapons to slugthrowers.

Christopher Phoenix (Mechanizoid) found a marvelous US Army study on vacuum firearms full of all sorts of interesting details. The report is titled "The meanderings of a weapon oriented mind when applied in a vacuum such as one on the moon" (1965), from the U.S. Army Weapon Command's Future Weapons Office. The US Army was working on a proposed Army base on the moon and figured the soldiers would need some kind of weapon that would work in the Lunar environment in case of invasion by a Foreign Power.

I will be using quotes from the report below, but as a gesture of mercy to my typing fingers and your reading eyes I will abbreviate it as "Moawomwaiavsaootm".


For an in-depth look at various firearm types past and future, I will refer you to the always worth reading Future War Stories:


In Moawomwaiavsaootm they note some common problems that people thought would crop up if a soldier tried to use a slugthrower while in the Lunar environment:

  1. The temperature ranges from -250°F to +250°F. This will drastically affect the bullet propellant, making the muzzle velocity wildly vary by 24 to 50%

  2. The high vacuum environment will make the blasted metal moving parts in the gun weld themselves together

  3. The lubricants will evaporate in the vacuum, leaving the mechanism unlubricated

  4. The low gravity will mean the weapon will have to be recoilless or it will kick the soldier head over heels

  5. The components of the gun will degrade dues to high vacuum and extreme temperatures

  6. A directed energy weapon (i.e., a laser pistol) may be the answer

The Future Weapons Office did some research and discovered that many of these problems were bovine excreta.

  1. With a bit of shade during the day and Earthlight at night, the temperature range will be a more reasonable -65°F to +125°F

  2. Vacuum welding requires the surfaces to be ultra-clean with no corrosion. There are protective coatings that will fix the problem.

  3. Yes, lubrication will boil away in vacuum. But in lieu of conventional lubricant, special surface films can be used. In addition, weapon should be constructed so that moving surfaces in contact are composed of dissimilar materials (e.g., metal on ceramic or plastic).

  4. Luna has a gravity 1/6th that of Terra. So as long as the weapon has a recoil which is 1/6th that of a comparable Terran-rated weapon, it does not have to be actually recoilless.

  5. Some materials do degrade under temperature extremes. So you use materials that don't. That is what science is for. Vacuum on the other hand has little harmful effect, if anything it strengthens metals.

  6. Yeah, a laser pistol would be nice but they are at least 20 years away. You'll see one around 1985 (Actually that was optimistic, I'm writing this in 2016 about 50 years from 1965 and we still don't got no ray-guns).

Recoil

If you are sure you won't hit anything but the space pirate, a standard handgun like a .45 automatic might do. One might think that the recoil would be uncontrollable in free fall, but both Dr. Schilling and Erik Max Francis are of the opinion that such recoil is vastly overrated. In a firefight, you'd be trying to keep behind some cover (or you'd be dead) so you'd be braced in some fashion. Any bracing at all would take care of the recoil.

Erik (working with somebody else's figures) calculates that the recoil will spin you at the minuscule rate of a few degrees per second. (bullet momentum 4 kg m/s, fired from 40 cm from the center of the axis, the angular momentum imparted to the marksman is thus 1.6 kg m2/s. Divide that by marksman's moment of inertia, and you get an angular speed of 0.05 rad/s, or less than 3 deg/s.)

If you wanted to use your handgun for propulsion, Trip the Space Parasite calculates that a .45 automatic will give 0.12 m/s of deltaV to a 50 kg person. I guess that means it will give 0.088 m/s deltaV to a standard 68 kg person. Firing the entire seven round magazine will give a 68 kg person about 0.71 m/s

And if you are a space pirate captain who often has to deal with mutiny, you might want to invest in a futuristic version of a duck's foot pistol. A sidearm that fires on all four barrels over a wide angle with one pull of the trigger is a great equalizer when you are outnumbered. Naturally a shot gun would work as well.

Moawomwaiavsaootm points out that since Luna has a gravity 1/6th that of Terra, a handgun with 1/6th the recoil will have about the same kick as a corresponding Terran handgun. Less effect, actually, since the shooter has 100% of their mass even though they only have 1/6th their weight.

Hearing Protection

James Borham has another often overlooked concern:

Speaking of bangs, one thing that virtually every sci-fi writer ignores is the fact that any boarding party is going to need hearing protection. Loud noises (like gunshots) are bad for ones hearing, and narrow metal corridors make great echo chambers, increasing the effect. A modern SWAT team uses suppressed weapons not for stealth, but to protect their own hearing. Anyone firing a weapon on-board a starship is going to have the exact same problem, only many times worse.

James Borham

Propellent and Lubrication

A conventional bullet has oxidizer inside the shell, it does not require atmospheric oxygen in order to fire. However, conventional handgun lubrication oil will boil away in vacuum, leaving a gummy mess. Unless special lubrication is used, the handgun is likely to jam. This is mentioned in The Venus Belt by L. Neil Smith, and also includes a mention of the effect of a 200 degree thermal shock the weapon undergoes when moved from sunlight into shadow. Thermotolerance of all components in the gun are important, many mechanical devices really don't like the idea of going from room temp to -60°F over a short period of time. The weapon might work shortly after it was brought out of the airlock, then suddenly seize up.

Evan Dorn notes that the lubrication question is not quite as bad as I make it out to be:

While thermal expansion might indeed be a problem, lack of lubrication probably isn't on the timescales important in a gunfight. The mechanisms of basic firearms are sufficiently simple that they will generally operate just fine without any lubrication at all, or even when coated inside and out with dust, grit, or mud. Lubrication serves only to reduce wear over the long term. One of the favorite "torture test" approaches used to demonstrate the durability of a firearm, in fact, is to disassemble the gun, clean all the parts with a degreasing agent, reassemble it, and put a few dozen rounds through it. (See e.g., XD Torture Test -- scroll down to "The Chemical Degreaser Test".) A revolver, in particular, has only three or four moving parts and should operate under almost any conditions.

Evan Dorn

In other words, vacuum will do terrible things to a handgun's lubrication, but we don't need no steeenking lubrication anyway. However, there seems to be some controversy on this point, with heated debate between the pro-lubrication and con-lubrication factions.

Moawomwaiavsaootm says that problem can be reduced if you ensure that all moving surfaces in contact are of dissimilar materials (e.g., metal on ceramic or plastic). In addition there are some special surface films that can be used instead of lubricants. It goes on to say that while some materials degrade under temperature extremes, others do not.

If one is merely transporting the weapon through a vacuum environment but does not intent to actually use the weapon in vacuum, James Borham has the solution:

On the subject of protecting guns from thermal shock and drastic pressure changes, we already have some experience. When a solider executes a HALO (high altitude, low opening) parachute jump, he goes from STP to a very cold, low pressure environment and back to STP in a very short time. The solution? Stick weapons and other equipment that wouldn't take well to the hostile environment in insulated, airtight bags. The insulation ensures the weapon might get cold, but won't suffer thermal shock, and the inside of the bag says at atmospheric pressure the entire time. The same could be done with weapons in space: in vacuum you would be limited to a knife, and some kind of laser pistol or specialized slug thrower, but once you get inside the other ship, you can simply unzip the bag on your chest and pull out whatever kind of gun you like (e.g. short barreled assault rifle, semi-auto shotgun, BFG 90000, whatever).

James Borham

Targeting

Back to András Bónitz:

Moving on, I would like to point out the XM29 OICW.

The predominant feature of this weapon, aside trying to combine an assault rifle and grenade launcher while expecting a soldier to lug it around without a problem, is the TA/FC. TA/FC stands for " target acquisition / fire control system" which is, simply put, a miniature ballistic computer with its own sensors ("computerized sight"). What makes it more unique is the Air Burst functionality. Air Burst means that it can program a lunched grenade to explode at a specific moment (with special grenade only, of course).

A scenario: two guys are hiding next to a window in a building. You have to take them out from afar and without alerting them. You can't just use a regular grenade, as it would go trough the window and into the far end of the room (possibly trough an open door that leads into a hallway), from where the effects of the grenade are lessened and the lethality is questionable at best. There is simply no good way to kill the two guys without risking alerting them.

Enter Air Burst mode. With the aforementioned computer, you can program the grenade to explode at the very moment it goes trough the window. The two guys experience the explosion and possible fragmentation directly. This can work with trenches and the like. The XM307 also has air-burst capability, and can be converted into a machine gun with the replacement of 5 parts.

The important thing is the sight: soldiers waste allot of bullets to take down one guy, up to hundreds. Since WW1, soldiers always wanted sights to better kill their enemies from afar. Nowadays, we have laser-assisted targeting and stuff like night vision sights and infra red to help find targets. A computerized sight is likely to appear in a futuristic setting.

This makes the idea of a firing system that checks whether you are shooting a soldier or an important piece of equipment much more plausible.

UPDATE: Actually, it already appeared somewhat. FN right now is making the rather sleek FN F2000 that also has a laser rangefinder with a computerized sight, usable by both the rifle and the attachable grenade launcher. The FN F2000 is one of the first ambidextrous bullpup, as the age-old problem of ejecting spent cases is solved by using an ejection tube.

András Bónitz

Gun Camera

Also, here is something interesting: Have you ever heard the idea of mounting a camera on your gun and aiming trough that? Well, SERO supposedly actually done that with the EOP system. (ed note: something like this has been suggested for hypothetical laser weapons.)

The EOP system was developted to deal with the prime problem of recoil. The .50 BMG or the similar 12.7mm M30 (Soviet equivalent of the latter) has enormous recoil, high enough that the user cannot fire from his shoulder. The only way to use it is by bracing it on a surface, like a ground or wall and that cannot be done if the squad is attacked suddenly.

The EOP (I wouldn't be surprised if other companies developed similiar optics) helps here: it allows the shooter to fire from the hip and thus respond quickly to any treat. It also allows the shooter to fire the rifle from behind cover without exposing himself.

The future of optics is here as well, not using glass optics but what is essentially a video camera with strong zoom capacity and possibly sensitivity within the IR ranges for night-time applications. The cost, reliability and battery power is what prevents this from entering regular service, but the future may bring different tidings.

András Bónitz

Other

There is also the matter of vacuum welding and evaporative bonding and outgassing from plastics, coatings for the barrel, propellants in the bullet. C. James Huff notes that a conventional firearm will overheat far more rapidly in vacuum, making an assault rifle practically worthless. James Borham points out that in vacuum a laser weapon will overheat even more rapidly than a conventional firearm.

Other novels mention special muzzle brakes that vector the exhaust in useful directions. These novels include Eon by Greg Bear and Nightrider by David Mace. They generally try to vent in an "X" pattern centered on the tip of the barrel with the arms of the X perpendicular to the barrel. This tries to stabilize the barrel while not allowing the exhaust to obscure the sight picture.

Also note that a handgun for vacuum use will require an over-sized trigger guard to accept a space suited finger. András Bónitz mentions that many pistols today have large trigger-guards for gloved hands. However, a space suited finger is huge compared to a gloved finger. Weapons that are intended for use in extreme cold climates sometimes are fitted with an "arctic trigger guard." This is a guard that can momentarily swivel out of the way or be unbolted and set to "arctic mode" to accommodate gloved hands.

Nightcrawler points out that revolvers might be popular in free fall, since other weapons eject their spent cartridges. Hot brass flying around the compartment could cause all sorts of problems. A cartridge floating inside a control panel and shorting out a critical component could ruin your entire day.

Nightrider

The assembled rifle was blunt and ugly. All rifles are ugly. It fired a low calibre round at super-high velocity, it was all breech and recoil-reloading mechanism, snub barrel and long muzzle brake. The butt was nothing, just a flat buffer pad. You held it two-handed like a police marksman but with the butt jammed against the chest of your suit, high up over the heart. The breech and the block magazine were behind the trigger grip so that it was back heavy when loaded, awkward to aim unless butted securely. To aim beyond point blank range you snapped the sights up and forward, open sights or else with an infrared or starscope aimer fitted—you couldn't crane your head to line up a shouldered weapon, not in a spacesuit. Aiming was easy unless you wanted to shoot for kilometres, when you had to use a laser ranger that imposed a trajectory lift on the sights. Closer to, the trajectory would be virtually flat in Hel's 0.6g, and with no atmosphere to retard it the bullet arrived as fast as it left the barrel. Which was very fast. And that achieved with a minimum recoil kick because of the muzzle brake. The design was just a further improvement of what was standard. The brake deflected the propellant gases into an X-cross of four streams, two angled up and two angled down, an arrangement that neither blinded your aim while firing nor seared your leg while kneeling nor killed the friend beside you. Handling the rifles was far too easy.

And the rounds were fearful. Pointed little four millimetre things, part solid bullet and part glued on caseless charge, such low bulk and weight that you could carry hundreds. Those bullets would go through the shell of their own suits. They would hopefully go through whatever the Outsiders wore. The bullet sheared and fragmented on penetrating a rigid suit, it shredded any flesh on the other side. If it hit unprotected flesh it tumbled, dumping all its momentum in shock waves. Bones struck directly disintegrated, others connected to them shattered, soft tissue was just exploded kinetically.

From Nightrider by David Mace (1985)

1965 Army Vacuum Firearms

This is from the US Army report Christopher Phoenix told me about.

The report was looking into slugthrowers that Army troops could use on Luna. They found it interesting to note that a bullet fired in vacuum retains all of its velocity, since there is no air resistance when there is no air. Here on Terra, the further a bullet travels, the more it slows down, and the lower the damage it inflicts.

Given the Lunar gravity a bullet fired horizontally from the shoulder of a person six feet tall (about 5 feet), the bullet will travel about 2.73 times its velocity before gravity pulls it down to the ground. For example, a bullet with a muzzle velocity of 3000 ft/sec will impact about 8190 feet away.

If instead of firing horzontally you fired it at a 45° angle to the surface, it would impact about 318 miles away, and have a maximum altitude of 79 miles.

At a range of 328 feet the bullet will only drop by 2.4 inches, so a complicated set of gun aimsights are not required.

Range Calculations

Lunar gravitational pull is 1/6th that of Terra, or 32.2 / 5 = 5.37 ft/sec2

Projectile traveling horizontally while being pulled down by gravity will have a range factor of:

d = sqrt[ (8 * Y) / g ]

where:

d = range factor
Y = projectile's initial distance above the ground (ft or m)
g = acceleration due to gravity on the planet (ft/sec2 or m/sec2)
sqrt[x] = square root of x
Obviously use either all feet or all meters, do not mix the two.

So if g = 5.37 ft/sec2 (Lunar gravity) and Y = 5 ft (handgun's distance above ground when held by 6 foot tall person) then the range factor is:

d = sqrt[ (8 * Y) / g ]
d = sqrt[ (8 * 5) / 5.37 ]
d = sqrt[ 40 / 5.37 ]
d = sqrt[ 7.45 ]
d = 2.73

This equation is where the "2.73" from the above sentence comes from.

To find the range of a projectile (i.e., the distance from the gun muzzle where gravity manages to drag the bullet all the way down to the ground), you multiply the projectile's muzzle velocity by the range factor. So if the muzzle velocity is 3000 ft/sec, the range of a bullet fired horizontally from an altitude of 5 feet in Lunar gravity would be 3000 * 2.73 = 8190 feet.

If you are not interested in an assortment of muzzle velocities, the total equation with a fixed velocity is:

d = sqrt[ (8 * V2 * Y) / g ]

with V being muzzle velocity (ft/sec or m/sec).


If you are not firing horizontally (angle with the ground is not 0°) then the maximum range is:

R = (V2 / g) * sin[ 2 * α]

where:

R = range
V = muzzle velocity
g = acceleration due to gravity on the planet
α = angle gun makes with the ground
sin[x] = sine of x

So if g = 5.37 ft/sec2 (Lunar gravity), V = 3000 ft/sec, and α = 45°, then the range is:

R = (V2 / g) * sin[ 2 * α]
R = (30002 / 5.37) * sin[ 2 * 45 ]
R = (9,000,000 / 5.37) * sin[ 90 ]
R = 1,680,000 * 1
R = 1,680,000 feet = 318 miles

This equation is where the "318 miles" from the above sentence comes from.


If you are not firing horizontally (angle with the ground is not 0°) then the maximum height the projectile will reach is:

h = (V2 / (2 * g)) * sin[ α ]2

where:

h = maximum height
V = muzzle velocity
g = acceleration due to gravity on the planet
α = angle gun makes with the ground
sin[x] = sine of x

So if g = 5.37 ft/sec2 (Lunar gravity), V = 3000 ft/sec, and α = 45°, then the maximum height is:

h = (V2 / (2 * g)) * sin[ α ]2
h = (30002 / (2 * 5.37)) * sin[ 45 ]2
h = (9,000,000 / 10.74) * 0.7072
h = 838,000 * 0.5
h = 419,000 ft = 79 miles

This equation is where the "79 miles" from the above sentence comes from.

It is also important to note that the Lunar escape velocity is only 7900 ft/sec. So orbital velocity is 7900 / √2 = 5600 ft/sec. Which is quite attainable by conventional firearms. Therefore Lunar firearms should have a muzzle velocity limited to less than 5500 ft/sec or so, to avoid filling Luna's orbital space with hazardous shrapnel. A bullet could easily destroy a satellite and seriously damage a spacecraft.

Bullets would not need to be sharpened to an armor piercing point in order to penetrate a flimsy space suit, but you might as well sharpen them in case you are shooting at a Lunar rover or habitat. There is a direct correlation between bullet penetration and lethality, since popping the target means death by asphyxiation. At the very least the target is going to lose interest with anything other than plugging the blasted bullet hole.


The images below are from the report, with the title "Possible weapon concepts whose feasibilities have not been determined but are presented as ideas to stimulate thining."

Note the huge triggers and lack of trigger guards, to allow use by a space-suited hand.


Spin Stabilized Micro Gun

Method of PropulsionPropellant
Projectile Weight0.0027 lb
Projectile Length0.78 in
Projectile Diameter0.14 in
Muzzle Velocity3000 to 4000 fps
Weapon Weight2 to 4 lb
Rate of FireSemiautomatic
No. of Rounds30 to 50
Weapon Length18 to 24 in
Weapon Width1.5 in
Weapon Height4 to 6 in

Spin/Fin Stabilized Sausage Gun

Method of PropulsionPropellant
Projectile Weight1 to 2 Grains
Muzzle Velocity3000 to 4000 fps
Weapon Weight1 lb or less
Method of IgnitionElectrical
Rate of FireSemiautomatic
No. of Rounds19 to 37
Weapon Length6 to 8 in
Weapon Diameter1.0 to 1.5 in
StabilizationSpin in Vacuum
Fin in Atmosphere

Sausage Gun #2

Method of PropulsionGas or Propellant
Projectile Diameter0.25 in
Muzzle Velocity3000 fps
Weapon Weight1 lb or less
No. of Rounds19 to 37
Weapon Length6 to 8 in
Weapon Diameter1.0 to 1.5 in
Method of FiringPuncturing of Seal or
Ignition of Propellant

Directed Gas Weapon for Close In Fighting

Range3 to 6 ft
Lethal AgentDirected Gases from
High Explosive Detonation
Rate of FireSingle Shot or
Semiautomatic
No. of Shots1 to 7
Weapon Weight1 to 2 lb
Weapon Length4 to 5 in
Weapon Diameter1.5 in

Spring Propelled Spherical Projectile

Method of PropulsionCompressed Spring
Projectile Diameter0.20 in
Muzzle Velocity1000 to 1500 fps
Weapon Weight3 to 6 lb
No. of Rounds20 to 50
Weapon Length18 to 24 in
Weapon Width1.5 in
Weapon Height6 in

Gas Cartridge Gun

Method of PropulsionGas
Projectile Weight0.0012 lb
Projectile Diameter0.33 in
Muzzle Velocity1000 to 1500 fps
Weapon Weight2 lb
No. of Rounds25
Weapon Length8 in
Weapon Width0.5 in
Weapon Height3.5 in
Pressure2000 psi

Gas Operated Needle Gun

Method of PropulsionGas
Projectile Weight0.0012 lb
Projectile Diameter0.20 in
Muzzle Velocity1000 to 1500 fps
Rate of FireSemiautomatic
No. of Rounds25
Weapon Length12 to 16 in
Weapon Width1.5 to 2.0 in
Weapon Height6 in
Pressure2000 psi

Ammunition

Caseless Ammo

Caseless ammunition is a firearm round minus the brass cartridge, instead having a sort of solid propellant moulded around the bullet.

Advantages include weight savings allowing more ammo to be carried (about 510 caseless ammo rounds weigh the same as 100 conventional) and not leaving any tell-tale brass cartidges during a black ops mission.

Disadvantages are serious. Caseless ammo requires specialized weapons, they will not work in a conventional firearm. The propellant casing can be easily cracked and ruptured by being dropped or being touched by fingers. This causes misfires, and fragments of cracked propellant are quite difficult to clean out of the weapon.

The most serious disadvantage is thermal. Conventional rounds actually use the spent brass as a heat sink, which is ejected from the weapon. Caseless rounds have no brass, so all the heat stays inside the weapon, overheating it. Eventually the heat causes the entire magazine of caseless ammo to explode in the user's face. This is called "cooking-off".

Future War Storis has a well researched article about caseless ammo.

András Bónitz has also be doing some studying of futuristic looking weapons.

First off, THE weapon of the (near-by) future. For settings that try to be quite realistic and want to show off a powerful weapon, then I would recommend the Heckler & Koch G11. It looks futuristic, it is futuristic and... it looks cool. It's also something that would make some gun nuts like me drool.

It was a experimental weapon that showed positive results. It was part of a research project to improve firearms issued to soldiers. The weapon is special in its ammunition: namely there is no casing for it, or more accurately, the casing is flammable thus removed when the bullet is fired. Among other things, this results in a higher rate of fire and increased accuracy, all while being lighter. These are the three most looked-after properties when it comes to assault rifles for the regular soldier, thus quite reasonably the next direction to go. Plus, you don't have to worry about spent shells because there are no shells. The only thing I can't get a hold of is the ballistic properties of the ammunition.

A curious thing about the G11 (aside the advantages of its caseless ammunition) was that it was designed to fire in burst mode. Burst mode means that pulling the trigger will fire sequentially a fixed amount of bullets (here, three bullets) and actually had a higher rate of fire in burst mode than in either semi-automatic (pull trigger = 1 bullet, for those that are unfamiliar with such terms) or automatic mode (pull trigger = bullets come until the magazine is empty or the trigger is released). This helps conserve ammunition and improve accuracy due to the mechanics of recoil. Supposedly, the recoil was felt only after the bullets left the gun.

After some research, it seems that based on the G11's caseless technology a sub-machine gun and even a pistol was also conceptualized and planned.

The G11's caseless ammunation was developed during the "micro-calibre craze" ,a subject beyond the scope of this document (but if you are interested, look up "Project Salvo"). Thus was why the bullets had the calibre of 4.7mm (4.7x36). Like most micro-calibres, lethality was questionable, a fact that was offset by the G11's burst mode. A single bullet may not cause enough damage to incapacitate a target, but three bullets will.

Since this may be hard to come by, here is the performance of the 4.7mm G11 bullet: it weighted 3.4 grams, had the sectional density of 0.210, had the muzzle velocity of 930 m/s with the energy of 1470 Joules and had the recoil impulse of 28. (Sectional density is the momentum of the projectile per square milimetre).

It should be noted that caseless ammunation is much more fragile than regular cased ammunation, a fact that plaqued many other attempts at caseless ammunation since. Dynamit nobel was able to create a stable-enough propellent to make the weapon battle-worthy.

One might wonder that if the weapon was so great and so interesting, why was it not adopted? The answer that it was about to be, but history interfered. The weapon was commisioned by the Bundeswehr, the armed forced of Federal Germany to replace their old G3 rifles. The G11 was extensively field-tested and was about to enter adoption when the Berlin Wall fell. Reunification drew away funds from many projects, including the re-arment of the Bundeswehr. H&K went nearly bankcrupt due to this (and was brought by Royal Ordance, Britain), thus it is understandable that it is rather unenthusiastic to try it again. However, attempts at caseless ammunation may see the light again or possibly underway already.

It might be ideal to increase the bullet's size and propellent loading if that were to happen. Something along the British EM-2's 6.5x43 or the current spec-ops special 6.8x43 Remington would be considered ideal, giving appropriate conversion to caseless ammunation.

The other end of the spectrum of using bigger bullets, is using small bullets but using them very fast. This is what resulted in the American-180.

The American 180 is very interesting because it uses a common ammunation, the 22LR, used for sport and small game hunting. The gun offsets the .22LR's lack of stopping power by simply using more of it, hence is large (starting from 165 to 270!) drum magazine. The game had the awesome firing rate of 1200 rounds per minute (compared to say, the MP5's 680 or the M16's 800), meaning that 20 bullets were fired in a single second! One .22LR may fail to incapacitate an opponent, but several will bring anyone down, even chewing trough body armour by sheer voloume. The weapon failed due to its high cost and possibly because it was unable to satisfy its niché.

I still very much like this weapon, mostly because it resembles the popular image of the "Chicago typewriter", the idea of a drumed Thompson taken out and sweeping the streets.

It appears that a company named Tactical Innovations INC has developed an "upper" for the M16 that is essentially a modern version of the American-180 and is sold online. Here is a video there that shows a man holding such a weapon one-handed, demonstrating the low recoil of the .22LR.

András Bónitz

Frangible Rounds

Mike Van Pelt says that if protecting the spacecraft from clumsy shots has priority, frangible rounds may be the answer. These have been suggested for use by armed airline pilots, who also worry about the damage done by stray rounds. The Glasser Safety Slug was invented back in the 1970's, the current state of the art is the MagSafe. The good news is that they affect human targets far more effectively than spacecraft hulls. The bad news is that the penetration is reduced to a point where the space pirate's arms can offer their torso significant protection. And if the pirate is wearing body armor your handgun has become almost worthless. To make it worse, certain types of space suits are almost as good as body armor.

Flechettes

Erik says another possibility would be some sort of flechette weapon. This is kind of a shot-gun that fires a swarm of darts instead of buckshot ("flechette" is French for "little arrow"). They look like nails. In the shell, a group of flechettes are held together by a plastic frame called a sabot, which falls away when the load exits the muzzle. Light flechettes are twenty to a shell, heavy are six to a shell. Like shotgun shells, they are good for causing large amounts of damage to the intruder in one's apartment, but failing to penetrate the wall so as to not annoy the neighbors. Unlike shotgun shells, they are good at penetrating body armor.

Well, the heavy ones are good at penetrating. James Borham has further details:

Light flechettes are only good against soft body armor; rifle plates will stop them cold. Additionally, light flechettes lack the stopping power of buckshot against unarmored targets.

I couldn't find any info about heavy flechette shells, but I would imagine they behave very differently from their lighter brothers. With each flechette having the mass of a 000 buckshot pellet and likely being made from very hard material (at least hardened steel, probably tungsten), these shells will exhibit rifle grade penetration against everything. On the plus side, everything includes hard body armor.

All around, a shotgun would be quite at home on a ship. Light flechette shells or light bird-shot would protect the ship from misses, while heavy flechettes or saboted slugs would provide penetration against heavy armor. Just remember your hearing protection! Shotguns can't be suppressed, and are very, very loud indoors.

James Borham

SF author Michael Z. Williamson begs to differ.

Actually, the first weapon suppressors (silencers) WERE for shotguns. There's no trick to silencing them, though it's a bit bulky.

Birdshot will not reliably stop a person. It generally causes a flesh wound only. There are no projectiles that will reliably stop a person and not also punch the wall.

Glasers are still considered better than Magsafe by many people, though the fad for both seems to be fading.

Michael Z. Williamson

Mr. Williamson cites The Box O' Truth as his source. They do test fires on a lot of weapons, for penetration and damage.

Shotguns

As for shotguns, its not just about flechettes and birdshot: there are a ton of various specialty shotgun shells, from signaling whistles propelled by the shotgun, through flares and incendiary rounds to fin-aided explosives!

Example of a possible future shotgun and fin-aided explosives Video: AA-12. World's deadliest shotgun

There are even various "crazy" rounds like the infamous incendiary Dragon's Breath, bolo (two balls connected by a piano wire, thus cutting anything in its path, obviously unpredictably), self contained TASER slugs etc.

Of course, these specialty shotgun rounds are exactly that: special rounds for a special purposes. If you want to kill something, you will obviously just use buckshot or slugs or some similar variant. My point is that a shotgun would truly be quite at home on a spaceship as it is a versatile launching platform for a variety of weapons. With a little imagination and microscopic amounts plutonium, you could make even more uses for it. For example, with using a blank shot you can MacGuyver a shotgun to shot a grappling hook for you! Granted, it would take a little bit of engineering to figure out how it would do that, but still, I would like to see a laser do that.

Thus for your typical space jockey getting from one bizarre situation to the next, it would be a handy weapon, even if more powerful and futuristic weapons are available.

In sci-fi terms, think of a shotgun as a low-tech equivalent of a phaser. It's "good for everything, great for nothing" type of weapon when it comes to roles, with one big weakness.

The main issue with shotguns, is that cannot reliably pierce (level 4) body armour in almost any (known to me anyway) loading. This is a very big limitation, because most armies nowadays have body armour. I am sure that someone, somewhere is likely to develop an armour-piercing slug, but why do that when your General Issue Assault Rifle can already penetrate most types of body armour by default? Explosive shotgun grenades may seem dandy, except that 40mm grenades can deliver far more ordinance and there is a weapon devoted to just that task.

However, for broad purposes, the shotgun is an attractive weapon. Assuming you can carry the rounds, you can hunt with it, you can blow a few things up, you can incapacitate someone with it and it can be a fearsome weapon in close- quarters. For starship crews that might not want to lug around 5 different weapons that all fit for only one role, this might be an attractive weapon, especially if they expect to do special missions.

Now, for some hardcore, semi-futuristic example of a shotgun, I'd like to point towards the NEOSTEAD.

The NEOSTEAD is a rather innovative pump-action shotgun: it has two tubes for ammo, meaning that you can put slug type X in one and switch over to slug type Y that's in the other without reloading. Can be handy if you intend to exploit the ups and downs of different rounds.

Oh, and the shotgun is bullpup, allowing a large barrel while not being very large. This makes it quite compact compared to other combat shotguns. The pump-action is rather unique so far (forward-backward rather than backward-forward), but has been described by those that fired such a weapon as faster than conventional pump-action weapons.

Plus, it looks cool and has enough polymer in it to be branded "futuristic".

As a closing note on shotguns, I accidentally stumbled upon the patent for their silencers.

András Bónitz

Explosive Bullets

On the note of bullets and shells, here is an old dream: explosive bullets!

Explosives bullets have also been mentioned in non-fiction or semi-fiction in Frederick Forsyth's "Day of the Jackal" (an assassin trying to kill the a French president and how he does it). In it, the Jackal (the assassin) and the Armourer (a black market master gunsmith) discuss their business. The Jackal not only needs a gun that kills someone, but a one-off, a gun made specifically for one job and for one set of circumstances. The Jackal needs to gun to be of certain sizes, so he can hide it in disassembled form. The Jackal has a specific container in mind that would make the gun pass without suspicion (the book is set in the 1960's, thus only manual inspection).

This greatly limits the gun's size, especially the bullet. The calibre and power of the bullet in question is just not powerful enough to assuredly kill someone with one shot and that's all the Jackal wants to do. The Armourer comes up with a suggestion of an explosive bullet that would keep the bullet's size but would cause severe internal damage.

Essentially, the Armourer takes a bullet, drills a small hole in it, pours a droplet of mercury into it and fills the lead right back up. The mercury's purpose is two-fold: first, when the bullet is fired, the mercury accelerates backwards into its cavity. When the bullet hits, the droplet is propelled forward in the bullet and tears the bullet apart, making lead spray outward, thus creating a cavity far larger than the bullet, causing massive internal damage. The book notes that these bullets are far too complex to be produced en masse unless done by a factory. That, and the fact that they are supposedly banned by the Geneva convention.

The secondary function of the mercury is to be hot mercury: poison, in case the target survives the shot (the book does not mention this).

András Bónitz

Thomas L. Nielsen (B.Sc. / Case Officer of the Danish Defence Acquisition and Logistics Organization, Weapons Technology Branch ) disagrees with the feasibility of the mercury rounds.

All the tests I have seen of this concept show that the effect of filling a bullet nose with mercury is just not worth the bother. It is at best no more effective than a standard hollowpoint bullet, and far, far more expensive.

Thomas L. Nielsen

Back to András Bónitz:

A "weaker" version of these are hollow point rounds and soft-headed rounds. Technically, these are banned by the 1899 Hague Convention (third declaration, if Wikipedia is to be believed), which is part of the Geneva convention. About how this law is actually observed and followed, I would recommend getting a law student to find out.

András Bónitz

Thomas Nielsen had these comments on hollow point rounds. First off, as he stated above, mercury rounds are not weaker than hollow points. Secondly, the proper term is "soft-nosed" rounds, not "soft-headed" rounds. Further:

Technically, the Hague Accord/convention only applies to declared warfare between undersigning nation states. Which means police, security forces, legally armed civilians, military forces engaged in "police actions", as well as, of course, the above-mentioned assassin, can use expanding/deforming bullets to their hearts' content. Most military forces, however, choose to follow the letter of the Hague Accord regardless of the type and scale of operation. See e.g. this document

Thomas L. Nielsen

Electrical Explosive

Nightrider

She skipped over an array of recoilless grenades and landed between the transfer lock and her own cubicle door. She looked at the grenades. They were just flat ended cylinders sitting on the ends of one-shot disposable firing tubes. No streamlining or flight stabilization was needed. There was no atmosphere down there, only gas-ice and water-ice and rock and ice-rock powdery surface and a smear collected through the long circling aeons, a smear of cosmic dust. The grenades had electric capacitor heads which would need charging up before storing away again in the lander—the lander's system couldn't supply the necessary power. The grenades were the first ever weapons type designed exclusively for space use. The huge electrical potential discharged almost instantaneously into whatever was hit—building structure or vehicle or whatever—causing dispersal currents that vaporized the material and inducing secondary intense and disruptive electric fields. All the energy was dumped into the target. In contrast explosives were debilitated in a vacuum, with no pressure damping to confine the force of the detonation and no medium to transmit a shock wave. Even if an electric charge grenade only hit near its target it would cause such thermal disruption of the ground that debris would fly as from a fragmentation blast. What it would do to people Kim didn't know. They hadn't shown her.

From Nightrider by David Mace (1985)

Limited-range Bullets

(ed note: could be useful if one wanted to limit firearm range inside a spacecraft. So that misses did not continue travelling until they punctured the habitat module hull.)

     PICATINNY ARSENAL, N.J. -- Three employees of the U.S. Army Armament Research, Development and Engineering Center, or ARDEC, were awarded with a U.S. patent for their proof of concept work on a limited range projectile.
     Brian Kim, Mark Minisi, and Stephen McFarlane filed collectively for the patent on May 7, 2013 and were notified of its approval on Sept. 1, 2015.
     The concept for the limited range projectile includes pyrotechnic and reactive material. The pyrotechnic material is ignited at projectile launch. The pyrotechnic material ignites the reactive material, and if the projectile reaches a maximum desired range prior to impact with a target, the ignited reactive material transforms the projectile into an aerodynamically unstable object.
     The practical use that the three men intended to apply the concept to .50 caliber ammunition. However, the patent covers the idea and technology behind the concept as a whole so it could theoretically be used in various calibers of small arms munitions.
     "We wanted to protect the U.S. government's interests and position," McFarlane said about filing the patent.

TRIAL AND ERROR

     Computerized modeling and simulation were performed to compare the inventive projectiles to the .50 caliber M33 projectile and the .50 caliber M8 projectile.
     "Conceptual designs were ran through and evaluated via modeling and simulation," Kim said. "Three concepts were submitted with the patent, however, not all were feasible," he said.
     "A proof of concept test was perfected and results indicated the need for concept refinement and pyrotechnic mix improvement," Kim said.
     The group states that there are significant benefits to the warfighter in using a limited range projectile.
     "The biggest advantage is reduced risk of collateral damage," McFarlane said. "In today's urban environments others could become significantly hurt or killed, especially by a round the size of a .50 caliber, if it goes too far."
     McFarlane said that the distance in which the round disassembles can be adjusted based on the choice of reactive material used. The benefit to this is that the round does not continue to travel, therefore reducing collateral damage.
     This benefit can best described as "a design programmed maximum range," McFarlane said.
     The ballistics also match and or exceed the standard round out to the max effective range of the round. In theory, the projectile may be any caliber from 5.56 mm to 155 mm.

HOW THE DISASSEMBLING PROJECTILE WORKS

     The concepts vary, however in theory the process would work like this:
     During launching of the projectile, pyrotechnic initiating material is ignited by energy produced by propellant in the cartridge case. Or, pyrotechnic initiating material may be ignited by energy produced by bagged propellant, if the projectile is a separately loaded projectile.
     Pyrotechnic initiating material ignites the reactive material. Prior to impact of the projectile or with a target, and while the projectile is airborne, energy produced by the ignited reactive material transforms the projectile into an aerodynamically unstable object. The transformation into an aerodynamically unstable object renders the projectile incapable of continued flight.
     In one concept, the projectile is rendered unstable by the melting of the copper jacket, which produces a highly irregular shape. In another, the projectile is rendered unstable by the separation of the cylindrical portion from the base portion and the separation of penetrator from the projectile assembly.

Smart Bullets

"Smart Bullet" is a general term for a bullet doing something more interesting than just following its trajectory, such as speeding up, slowing down, sending data, etc. More relevant to our interests are bullets that can home in on their target (for increased accuracy or if the target is trying to evade). Some homers require the human operator or a forward observer to paint the target with a laser designator, the bullet homes in on the laser dot. Fancier bullets are self-contained, they are "fire and forget."

In the 1985 movie Runaway the smart bullets were programmed to home in on a specific person's thermal signature. The bullet would merrily chase the victim, dodging other people and following them around corners.

Sandia National Laboratories has announced a bullet that can track a target illuminated with a laser designator.

DARPA's Extreme Accuracy Tasked Ordnance (EXACTO) program has been working on a fire-and-forget system since 2008, they did a test firing in 2014, but no technological details have been released.

Gyrojet

The good old MBA Gyrojet pistol (1968) is worth looking at. This out of production weapon actually fired rocket bullets. The tail jets were angled to spin the rocket bullet in lieu of rifling. Conventional rifling in the barrel cannot be used since rocket bullet does not have enough initial energy.

It had some advantages:

  • It had practically no recoil, about 1/10th a Colt M1911 (but alas, as we saw, recoil isn't a problem in freefall).
  • It is more quiet than a conventional firearm. It makes a soft noise comparable to the "pfhsssssssst!" sound of opening a can of carbonated beverage. It does make a "crack" nose when the round goes supersonic; but this happens far in front of the firer, not right at the muzzle.
  • The weapon is low mass, since the barrel is never pressurized the firearm can be made out of lightweight alloys or even plastic. The original model was made out of an inexpensive zinc alloy called Zamak. A naive target glancing at a threatening Gyrojet might mistake it for a child's toy, at least until the rockets started flying.
  • The firing mechanism has fewer moving parts than a conventional weapon so therefore is less prone to jam. Fewer parts also allows higher firing rates.
  • Most of the bullet's propellant is burned during flight outside of the weapon, with much less heat build up. This as well allows higher firing rates, up to 60 RPM.
  • Since the precision and high-pressure parts are all in the rocket shell, the weapon itself can be constructed out of low precision die-cast or stamped parts. This also simplifies field repairs. It also has the result of making the weapon relatively inexpensive but the ammunition more expensive.
  • The rocket propellant is clean burning leaving little or no residue. Hundreds of rounds can be fired before the weapon requires even minor cleaning.
  • The flame of the rocket is only visible from behind, so while the firer can see it the target cannot.

Problems included slow burn times. This meant if your target was too close, the bullet didn't have enough time to get up to a speed capable of damaging it. If the target is only 0.3 meters or closer the bullet will probably limply bounce off, fall down, and spin on the ground spitting sparks like a dud firework. The bullet only got up to full speed after it had traveled about 9 meters, which is a bit excessive. Especially considering that average range of a confrontation with a handgun is about 2 meters. At that range a gyrojet round would have a pathetic penetrating power of about 80 joules, about the same as a .22 Rimfire Short cartridge.

For these reason some say the Gyrojet should have been marketed as a long-arm rifle, not as a pistol. The problem could be fixed if a faster burning propellant was subtituted.

The MBA Gyrojet also had poor accuracy. As it turns out, that was due to the MBA ammunition, not because rocket bullets are inherently inaccurate. The MBA ammo suffered from shoddy manufacturing and poor quality control. The main problem was that the bullet's nozzles were not aligned with each other, forcing the rocket off target. The fact that 1% to 10% of MBA's manufactured rockets would misfire didn't help either.


But with some development, the weapon might be redeemed. The Deathwind project is attempting to create the next generation of gyrojet weapons. Or if you prefer the brute-force approach, the rocket bullets could be enhanced with explosive warheads or made into radar-guided missiles, heat-seeking missiles, or smart bullets.

Coridon Henshaw suggests special fusing for the explosive warheads, so the shaped charge will go off if they contact flesh or body armor, but not if they hit the hull. He says another possibility is a multispectral sensor and sighting laser that will disallow firing if the line of sight ends at something that is part of the spacecraft. Include a manual override in case some diabolical space pirate figures out how to make their body armor look like hull plates.


The pistol had a mass of 0.4 kg (as compared to the Colt M1911 with a mass of 1.1 kg). The over-all length was 27.6 centimeters, with the barrel being 13 cm. The pistol holds six rounds in the magazine, which was regrettably not a removable magazine. The weapon had to be loaded by opening the bolt and feeding rounds into the magazine one-by-one, which made quick reloading impossible.

Gyrojet
Round
ChargeWeightMax VelDmg
13 mm Standard (@2m)2.9 g12.0 g80 j
13 mm Standard (@9m)2.9 g12.0 g380 m/s950 j
13 mm High Velocity7.1 g 7.1 g700 m/s1690 j
13 mm Heavy Weight0.9 g20.1 g120 m/s150 j
13 mm Target0.2 g 7.1 g120 m/s50 j
13 mm Std Long4.5 g17.8 g450 m/s1900 j
20 mm Standard6.5 g43.7 g330 m/s2580 j
Conventional
Round
WeightMax VelDmg
.22 Short 1.9 g340 m/s 80 j
9mm (Luger Parabellum) 7.5 g350 m/s450 j
.45 ACP (Colt M1911)14.9 g260 m/s500 j
.38 Special 9.7 g320 m/s520 j
.357 Magnum10.2 g430 m/s940 j
.44 Magnum (AutoMag)15.6 g450 m/s1560 j

Each .50 caliber rocket "bullet" had a mass of 9 grams (6.65 grams of rocket + 2.5 grams of propellant). The most common rounds were 13mm (0.51 caliber), though others ranged from 2.8mm to 40mm. Each rocket has a low velocity at the point where it exited the muzzle, but by the time it had traveled 9 meters (0.12 seconds after ignition) the propellant had all burnt and the round had accelerated to its full velocity of 380 m/s. The kinetic energy delivered to the target was about 950 joules. By way of comparision a Colt M1911 .45 ACP bullet delivered from 477 to 835 joules and an AutoMag .44 Magnum bullet delivered between 1000 and 2000 joules. However, as previously mentioned, at a range of 2 meters (average range of a confrontation with a handgun) the round would only be fast enough to deliver a disappointing 80 joules.

Effective firing range was about 50 meters. Keep in mind that if the rocket hits something before the propellant is spent, the 5000° F exhaust might ignite the target.

The propellant was a double-based nitrocellulose propellant. These cannot explode, just burn. A composite or metalized propellant was rejected because the magazine would tend to explode if you dropped the weapon or box of ammo. The latter propellants also had toxic and corrosive exhausts, another reason to reject them. The double-based nitrocellulose propellant charge in the round produced a maximum thrust of 33 newtons. The thrust-to-weight ratio was about 284 to 1. The rocket accelerates at something close to 600 gs.

The final advantage of double-based nitrocellulose is that it is smokeless. However, on a cold day the rocket will leave a contrail of condensation.

The angling (port angle) of the rocket exhaust jets is a tricky design task. It divides the rocket thrust into two components: forwards thrust and angled thrust. The forwards thrust propels the bullet towards the target to inflict damage, the angled thrust spins the bullet for gyro-stabilization. The problem is deciding how to divide the thrust between the two components. Too much angled means too little bullet velocity delivering damage to the target. In addition too much angled could spin the bullet too rapidly, causing it to actually disintegrate in midair due to hoop stress. But if too little of the thrust is angled there will be not enough spin for proper gyro-stabilization. Most gyrojet rounds have a port angle of 15°, so 85% of the thrust was in forwards motion and 15% was used for spin. The standard gyrojet round spins at a rate of 3600 revolutions per second (216,000 rpm).

Nowadays designers would probably not bother to use spin gyro-stabilization at all, instead they use smart bullets.

The rocket's case is made of high tensile strength steel to withstand the 17,000 kilopascals internal pressure from the propellant, and the hoop stress of spinning like a top on steroids at 3600 rps. MBA was experimenting with a Gyrojet "shotgun round", where a wad in the nose would hold the pellets, and the wad designed to disintegrate under hoop stress and internal propellant pressure.

The Gyrojet did have a remarkably jam-proof design, due to the small number of moving parts. Instead of a movable firing pin struck by a hammer, there is a fixed pin at the back of the chamber. The hammer strikes the front of the rocket, forcing it back onto the fixed firing pin. The rocket's primer strikes the firing pin, igniting the rocket's propellant. The rocket shoots out the barrel, simultaneously re-cocking the hammer (this steals about 10% of the 13mm std rocket's energy). The hammer is initially cocked by thumbing a lever on the side of the sidearm, in an arc-like groove above the trigger. The cocking lever is on the left side of the weapons, which makes it awkward for left-handed people.

A lip at the top of the walnut handgrip forces the thumb to be straight and low. Otherwise when the trigger is pulled, the cocking lever on the hammer will slam up and injure the hapless user's thumb-tip.

Once the hammer forces the rocket onto the firing pin, it also momentarily restrains the rocket in place. This gives the rocket a chance to "spin up" enough to be gyro-stabilized. Otherwise the rocket would emerge from the barrel unstabilized and accuracy would be impossible.

Unlike conventional designs, the Gyrojet firing mechanism does not need a reciprocating bolt, an extractor, or an ejector. This results in a much lower part count for the firing mechanism, and far fewer ways to jam. The firing mechanism requires no lubrication, and will still operate if the weapon is contaminated with dirt, mud, or other debris.

The weapon's safety switch raises a metal obstruction to cover the firing pin. Unlike a conventional safety, it does not lock the hammer and trigger, which is a rather unreliable solution.

Misfires were a problem as well. You could either manually re-cock the hammer and try again, or open the slide and remove the defective rocket. Be careful opening the slide, the magazine spring will try to eject all the rockets like a jack-in-the-box. Also be careful opening the slide because if the defective rocket is a hangfire, it will suddenly launch into your face (owner's manual recommends a ten second wait). The MBA Gyrojet design could use some improvement.

A gyrojet barrel should be smooth-bore, no rifling is required. MBA put decorative rifling in anyway because of a stupid provision of the 1962 National Firearms Act would have added a tax on the weapons (with no rifling a gyrojet would be classified as Title Two 'Any Other Weapons'). The Mark I gyrojet rounds were 13mm or 0.511 caliber. This would run afoul of the 1968 Gun Control Act, which classifies weapons with a bore diameter greater than 0.50 caliber as "Destructive Devices." MBA responsibly got permission from the BATF to convert unsold 13mm gyrojets into the Mark II version with 12mm rounds, or 0.49 caliber. Later the BATF fixed the problem by classifying gyrojets as "Curios & Relics".


What caused the MBA company to go bankrupt was the fact that the military didn't want the Gyrojet, and there was no civilian market for a weapon whose ammunition costs over a dollar a shell, with no possibility of re-loading the shells.

There was a a 12mm gyrojet underwater spear gun (called the Lancejet), a snub-nosed survival gyrojet pistol, and an over-and-under derringer modified to accept a gyrojet round in the upper barrel. Like the original gyrojet none of them caught on either. There was also an insane experiment with a "volley gun" variant, which simultaneously fired 12 nine-millimeters rockets with one pull of the trigger.

(ed note: this is not from a novel, this is reality. Tim Bixler purchased his first gyrojet in 1965.)

I once took my Gyrojet out there, number 67, and the scuba gear. I jumped off of the police boat and went down about, I don’t know, five or ten feet, and I shot the Gyrojet underwater. It was really, really neat. The bullet went out but it left a spiral trace of bubbles from the four rocket nozzles. As the rounds got farther out, I imagine about five or ten feet, but this has been a long time, the bubbles expanded. When I looked where the round had been, and I have no idea how far it went but probably not too far after the burn out, the bubbles kind of expanded. It was kind of like looking down the big end of a megaphone. That’s the best way I can describe it. As they were expanding, they were also deforming. The bubbles were trying to float up. I can’t describe it better than that, but boy was it neat.

After shooting a few rounds like that, then, from about five feet under water, I shot a couple up into the air. They went to the surface but the bubbles didn’t deform the same way. Since they were going up, the spirals stayed round. You probably don’t care about all this but it was neat and I am reliving all this in my mind as I tell it.

Anyhow, after I shot five or ten more rounds, I came up and my partner on the boat said, “Man! What were you doing?” I said I was just playing with this gun I got. He said, “Things were coming out of the water going 'phew' up in the air.”

It put me in mind of the atomic submarines launching missiles. I know that’s an exaggeration but it was neat.

From Gyrojet Recollection of Tim Bixler, by Captain Monty Mendenhall

Rocket guns are very simple contrivances so far as the mechanism of launching the bullet is concerned. They are simple light tubes, closed at the rear end, with a trigger-actuated pin for piercing the thin skin at the base of the cartridge. This piercing of the skin starts the chemical and atomic reaction. The entire cartridge leaves the tube under its own power, at a very easy initial velocity, just enough to insure accuracy of aim; so the tube does not have to be of heavy construction. The bullet increases in velocity as it goes. It may be solid or explosive. It may explode on contact or on time, or a combination of these two.

From Armageddon 2419 A.D. by Philip Francis Nowlan (the original "Buck Rogers" novel) 1928

The Gyrojet: an ancient toy or weapon, depending. It was a rocket pistol, made during the 1960s, then discontinued. This one had been stolen from someone's house and later sold to McAllister, secretly, a full twelve years ago.

A rocket pistol. How could any former Buck Rogers fan have turned down a rocket pistol? He had never shown it to anyone. He had had the thought, even then, that it would be untraceable should he ever want to kill somebody...

The true weapon was the rocket slug. The gun looked like a toy, flimsy aluminum, perforated down the barrel. Anderson might have thought it was a toy—but Anderson was bright. He got the point immediately. He turned to run.

McAllister shot him twice in the back.

(ed note: In the original 1928 Buck Rogers comic strip, the American freedom fighters are armed with rocket pistols, while the sinister Mongol Hordes have deadly disintegrator rays.)

"The Alibi Machine" by Larry Niven (1973)

Bullpups

Nightcrawler has found several marvelous firearms that were perhaps ahead of their time, but never quite made it. They would be very appropriate for a classic future setting. Nightcrawler advises anyone doing research into such historical firearms to go to Maxim R. Popenker's the "Modern Firearms & Ammunition" site.

Most of these firearms feature the "bullpup" arrangement, where the magazine and the action (mechanism) are behind the handgrip and trigger, instead of in front as is conventional. This shortens the weapon's total length and improves the balance. As a drawback, most bullpups have a specific "handedness". If a left-handed shooter tries to fire a right-handed bullpup, the bullpup will insert the red-hot spent casing up their nose, grab their ear, and attempt to load it into the firing chamber. RanulfC tells me that 90% of all bullpup designs can be easily reset from one handedness to the other.

In the AUG case, pop one pin, pull the charging lever/ejection port forward, rotate, push back in and seat pin. Done.

RanulfC

For an in-depth look at advantages and disadvantages about the bullpup, read Anthony Williams' article.

Korobov TKB-022

I'm very familiar with firearms of most types, and I honestly have no idea how this thing feeds or ejects. It's possible it uses some kind of ejection tube, where the brass falls out of the front, but that's only a guess.

Nightcrawler

The Korobov TKB-022 has a vertically moving breach and it ejects out the front, above the barrel, as noted [on "Modern Firearms & Ammunition"]. The relevant text is quoted below:

"The TKB-022 assault rifle is gas-operated weapon with annular gas piston located around the barrel. To achieve minimum length, it is assembled into bull-pup configuration and uses vertically sliding bereech block (bolt), rather than traditional and most common bolt that cycles back and forth. Since the movement of the bolt (breechblock) in this design cannot be used to extract, eject and load cartridges, Korobov developed a special U-shaped rammer / extractor, that strips the frech cartridge from magazine, pushes it into the chamber, then, after the discharge, pulls the fired cartridge case back from the chamber. Upon feeding the next fresh cartridge, the fired case is pushed forward and slightly up, into the ejection chute above the barrel. Spent cases finally fell off the gun above the muzzle. Gun was capable of full- and semi-automatic fire, with combined safety / fire mode selector switch located above the trigger on the left side of the gun. The gun housing was made from reddish-brown plastic, with metall structure hidden inside."

Josh P

Afanasiev TKB-011

Note the angled-forward ejection, allowing left-handed use of the rifle.

Nightcrawler

LAPA FA 03

An experimental Brazillian design from the 70s.

Nightcrawler

Enfield EM-2

Was formally adopted by the British but never put into service. The idea of a service rifle equipped with an optic and utilizing folding back-up iron sights is accepted now, but it was far ahead of its time when the Enfield was designed.

Nightcrawler

High Standard HS-10

A bullpup autoloading shotgun with a built-in light. Weapon lights are common now (and likely would be in space, because it's dark on a ship if the lights go out), but this design was ahead of its time. It would have been better served with a full-length magazine tube, allowing it to hold more shells.

Nightcrawler

Looking Futuristic

The firearms in this section are here mostly because they look like something out of a science fiction movie. Indeed, in some cases these weapons commonly appear in low-budget science fiction movies because they happen to look futuristic.

Keep in mind though that when a SF movie director on a budget uses "exotic" (i.e, not commonly encountered in the United State) firearms as props instead of making them from scratch, they run the risk of the infamous "I Know That Gun" problem. This is when you get a steady stream of gun enthusiasts pointing at the movie screen while saying "I know that gun..." There is a nice list here, and another one here.

Whitney Wolverine

In the "visually impressive" department, we have the Whitney Wolverine. At .22 calibre it has no stopping power, but boy, does it does it look futuristic!

The legendary Gharlane of Eddore once said:

Or how about the Whitney "Wolverine," the .22 pistol from about forty years back that looked like it had come from sixty years in the future? I once helped out a friend in dire need of hand-props for a SkiFfy movie by suggesting he use some of those. Saved him a bundle.... the problem was prying them loose from the actors so we could return them to the folks we'd rented them from!

David G. Potter

In reference to the top picture at the right he said:

Note that the picture is one of the blued/anodized models; the ones you want to use as hand-props in SkiFfy movies are the stainless-steel and passivation-anodized ones, a creamy silvery color with iridescent rainbow highlights. some production runs used a magnesium-aluminum alloy shroud which wouldn't take bluing, but anodized nicely, in some very pretty colors.

David G. Potter

Interestingly enough, the Whitney Wolverine is now back in production from Olympic Arms.

The pistol grip of the Wolverine may look weird and futuristic, but it has an ergometric design, and is reportedly quite comfortable to hold.

Beretta U22 Neos

Recently, the Beretta company released a target/plinking pistol with the same futuristic look as the Whitney Wolverine. Called the U22 Neos, it too would not look out of place in a spacecraft.

Lone Eagle

Zathras9 brought to my attention another visually impressive firearm: the Magnum Research Lone Eagle.

While this is a single-shot breech-loading target pistol, it chambers rifle ammunition with five times the volume of a comparable caliber pistol round, making it a heavy hitter. With only minimal alteration, the design would work as rocket-firing pistol, especially if the telescopic sight contained a dedicated ballistic computer.

One could even make a good case for keeping it a single-shot breech-loader rather than a magazine-fed design like the GyroJet: it's probably not a good idea to have multiple round of volatile ammunition contained within the weapon at all times. Better to keep the rockets that it fires in a separate container and load and fire the weapon only when necessary.

This might be even more credible it fired a wide variety of rocket types: anti-personnel, armor-piercing, biochemical, concussion, explosive, gas, incendiary, marking, netting/binding, smoke or thermonuclear. There's even a precedent of sorts in the "Caster" using in the anime/manga series Outlaw Star, although that fired magical spells rather than technological warheads.

If I were making a 80th anniversary Buck Rogers movie, this is what I'd use for the standard-issue rocket pistol.

Zathras9

Cosmo-Dragoon

The weapons can also have a mystique about them. Pictured is the legendary Cosmo-Dragoon from the anime of Leiji Matsumoto. His astro-automatic is a variant on this. The weapon was modeled after the Colt 1848 Dragoon Pistol. In his anime, there are only four of these weapons in existence, and they are the only weapons capable of killing a machine person. It is truly a space warrior's gun.

Palm Pistol

This was another one of those times when Bigman was glad he carried a needle- gun even in the face of Lucky's disapproval. Lucky considered it an unreliable weapon, as it was too hard to focus accurately, but Bigman would sooner doubt the fact that he was as tall as any six-footer as doubt his own skill. When Summers didn't turn at Bigman's shout, Bigman clenched his fist about the weapon (of which only half-inch of snout, narrowing to a needlepoint, showed between the second and third fingers of his right hand) and squeezed just tightly enough to activate it.

From Lucky Starr and the Moons of Jupiter, by Isaac Asimov

Special Purpose Individual Weapon

The US Army experimented with light-weight, high velocity projectiles in the 1960s. The big downside to such projectiles is poor penetration. Lacking momentum, featherweight flechettes are easily deflected when fired through intermediate barriers (walls, trees, etc.).

Nightcrawler

XM8

Nuwan Weerahandi mentioned the XM8 rifle, a modular rifle system under development by the US Army. One of the XM8's unique features was its modularity. This modularity allowed for quick repairs, barrel length changes, and even caliber changes in the field. But for our purposes, it is admirably futuristic looking.

Beretta Cx4 Storm

I'm sure there are many other sci-fi looking weapons out there, but I thought I'd call your attention to a few in particular. The Beretta CX4 storm carbine, since I own one in .45 caliber. It certainly is a very futuristic looking weapon. Add a few accesories, like a tactical light & a scope and you have a future SWAT weapon. The ejection port & the cocking handle can both be swapped side to side.

Detscorach

Kel-Tec SU-16

A few weapons that would look right at home on the set of Bladerunner is the Kel Tec SU 16 C. Or the Kel Tec 16 D.

Detscorach

Kel-Tec PLR-16

But for real Bladerunner looks, you can't beat the Kel-tec PLR 16 pistol. Comes from the factory looking like it has Deckard's name on it!

Detscorach

Calico

Steyr AUG

Ludicrous Weapons

Pistol to Carbine

The Neos has an optional kit that will convert the pistol into a carbine. People who grew up in the 1960's will quickly spot the similarity to the U.N.C.L.E. Special carbine, arguably the most famous of all TV show weapons. And though it was never shown in an episode, the carbines used in the cartoon Johnny Quest can telescope down into a pistol.

Infantry Gattling Guns

Oh, yes. One more thing: please make a footnote or something about infantry-portable gattling guns. They do not make sense on many, many levels, most importantly, there are already machine guns that have overwhelming firepower. There is simply no need for such a weapon.

András Bónitz

Gauss Rifles

Gauss Rifles are man-usable coil guns, standard coil guns better suited to arm warships with. No, they are not railguns, the explosive arc between the rails would probably instantly kill the weapon user, even if they were wearing powered armor.

Basically coil guns propel their bullets with electromagnets instead of gunpowder.

Future War Stories has a penetrating article about gauss guns.

Most older science fiction fans first encountered these in the role playing game Traveller.

The main problem is that gauss rifles share a problem with laser weapons: they are electricity hogs. They need either a few breakthroughs in battery technology or a very long extension cord.

There also is no clear way to spin the projectile for gyroscopic stabilizing. This is where the word "rifle" comes from, the rifling grooves inside the barrel that force the bullet to spin. But perhaps the coil gun projectile is moving so fast it doesn't need any gyroscopic stabilizing.

Currently there exists no coil gun weapons because nobody can find a good solution to the switching problem.

(ed note: somebody asked Luke Campbell about a hypothetical coilgun with a 5mm round fired at 1.5 km/sec)

Note that a 5mm needle is not much narrower than current bullets army grunts shoot out of their service rifles.

Still, if I plug the numbers into my rough interpolation formulae, I get something like:

5mm x 25 mm tungsten needle, 9.3 grams, 1.5 km/s

  • Muzzle energy 10.5 kJ (about 6 times the energy of an M16 bullet)
  • Armor penetration about 6 times that of am M16
  • Penetration through meat of about 3 times that of an M16 (not that this matters, both can punch all the way through a man with plenty of oomph left over)
  • Loses half its kinetic energy after flying about 400 meters.
  • Assuming a 5 kg gun, the felt recoil is about 5 times greater than that of an M16. The recoil momentum transfer is about 4 times greater than that of an M16.

This seems to be a lot of overkill for a typical grunt's service rifle. You could, for example, go with something like:

2.75mm x 20.6mm tungsten needle, 2.33 grams, 1.7 km/s

  • Muzzle energy 3.36 kJ (about 1.8 times that of an M16).
  • Armor penetration about 3 times that of an M16.
  • Penetration through meat about the same as that of an M16. With a fragmenting bullet, it would produce a wound cavity of about twice the volume as an M16's fragmenting bullets.
  • Loses half its kinetic energy at about 300 meters.
  • Felt recoil about the same as an M16, assuming a 4 kg gun. The recoil momentum transfer is also about the same.

Gauss weapons would greatly reduce the need to clean the barrel of your needle gun, since you won't have burning junk gunking up the inside of the weapon, but this forces you do deal with energy density issues to fire the weapon.

Mark Graves

Triplanetary

This is total space opera without a scrap of real science, but I couldn't resist.

Going up to a blank wall, he manipulated an almost invisible dial set flush with its surface, swung a heavy door aside, and lifted out the Standish — a fearsome weapon. Squat, huge, and heavy, it resembled somewhat an overgrown machine rifle but one possessing a thick, short telescope, with several opaque condensing lenses and parabolic reflectors. Laboring under the weight of the thing, he strode along corridors and clambered heavily down short stairways. Finally he came to the purifier room, and grinned savagely as he saw the greenish haze of light obscuring the door and walls — the shield was still in place; the pirate was still inside, still flooding with the terrible Vee-Two the Hyperion's primary air.

He set his peculiar weapon down, unfolded its three massive legs, crouched down behind it, and threw in a switch. Dull red beams of frightful intensity shot from the reflectors and sparks, almost of lightning proportions, leaped from the shielding screen under their impact. Roaring and snapping, the conflict went on for seconds, then, under the superior force of the Standish, the greenish radiance gave way. Behind it the metal of the door ran the gamut of color — red, yellow, blinding white — then literally exploded; molten, vaporized, burned away. Through the aperture thus made Costigan could plainly see the pirate in the space-armor of the chief engineer — an armor which was proof against rifle fire and which could reflect and neutralize for some little time even the terrific beam Costigan was employing. Nor was the pirate unarmed — a vicious flare of incandescence leaped from his Lewiston, to spend its force in spitting, crackling pyrotechnics against the ether-wall of the squat and monstrous Standish. But Costigan's infernal engine did not rely only upon vibratory destruction. At almost the first flash of the pirate's weapon the officer touched a trigger, there was a double report, ear- shattering in that narrowly confined space, and the pirate's body literally flew into mist as a half-kilogram shell tore through his armor and exploded.

From Triplanetary by E.E."Doc" Smith.

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