Guns on the moon

as the title says, how can one get a gun of some kind to work on the moon.

first: can it be done? as i see it yes it can as long as it has its own oxidizer or it does not need Oxygen to explode, or rather as we need it to do here, Detonate.

Second: should i bother?

the way i see i have two options when it comes to guns,

first is the tried and true bullet, AKA mass times acceleration equals Bleep you!

second are lasers which should do better given there no air to screw with them.

third: what do you make it cope with moon dust, which is like powdered glass from a endless time of asteroid impacts.

As I understand it, you might get it to fire off once, and then all the lubricant and shit will freeze and you won't have any oxygen to fire it off with.

You'd be better off with a speargun, though, methinks. You only need to puncture the suit of the other person, not score a legit fatal blow...

I'm trying to find the article on the matter. It says modern guns will work in space. Also had an amusing photoshop of an astronaut with an AKM.

Both black powder and smokeless powder are self-contained in their oxidizer; they can fire in vacuum just fine. Vacuum will not cause lubricant to freeze; it's not actually cold, it's an insulator. It might cause it to boil off, but grease has pretty darned low volatility; I'd think on first guess that it'd be all right. Nothing I can think of off the top of my head prevents standard Earth guns from working on the moon. (It's a lot easier on the moon than in EVA in orbit; you don't have to worry about flying off in the opposite direction, though if you're unbalanced you might fall over due to recoil.) Of course, I can't imagine hot brass flying around would do anything good for space-suiting people, and many of the standard tasks for Earth guns require dexterity that you'd be hard-pressed to achieve with current vacuum suits, so you do have to deal with those issues.

I'd second the speargun idea, all the myriad dust and things that could jam a gun's firing mechanism isn't something I'd want to deal with, irl or as a writer

Would make for an interesting Chekov's Loci though

Well, if you really want to use a gun in an environment that needs a lack of recoil...

A gyrojet weapon launches small spin-stabilized rockets from what is for all other intents and purposes a normal firearm, with the original designed for 13mm caliber though 6mm was proposed. They're a pretty interesting design from a technological standpoint, and they could be made significantly better than the 1960s version with more modern manufacturing technique and better quality control. The initial acceleration problem (unlike a bullet, a gyrojet rocket starts slow and speeds up) and consequently minimum effective range could be solved with an explosive warhead. Even a very small one would be sufficient to damage a spacesuit and either kill the wearer or render him more concerned with getting inside because part of his suit's depressurized.

edited 30th Apr '12 4:57:39 AM by Night

I still say speargun. You can attach a spear to a line so you can retrieve it if you miss.

Spearguns are likely to have quite a bit less range and be quite a bit more conspicuous and unwieldy, not to mention the inability to carry around large amounts of ammunition.

Re: gyrojets: I had the idea from somewhere that the rockets required air to function, something about providing a channel for air at supersonic speeds or similar, but I can't find a source now that mentions whether they needed that or not. If they were functional in vacuum they'd be quite effective.

...that doesn't make a lick of sense. We could never have gone to the moon, established orbit, and then broken it to land, take off, reestablish orbit, break it to come back...

Basically the Apollo program craps all over that idea.

humm, I never thought about a spear gun. Neatly side steps the dust issue as well.

Forgote about the Gyrojet as well, (PS putting a explosive on it makes it a space marine bolt gun.) though the problem of lunna dust gumming up the inside of it is still a problem.

for reference here is an article.

http://www.sciencedaily.com/releases/2008/09/080924191552.htm

The gyrojet actually has remarkably few moving parts to jam, primarily because it doesn't eject spent casings. Unless you jam it barrel-first into the ground or bury it, I don't think the dust will be a problem. Some of the pistols were used in Vietnam and they were models of reliability in terms of actually working when you pull the trigger.

A revolver would work.

A modern firearm contains its own oxidizer in its sealed cartrige, and they (revolvers) dont have the delicate parts of semi-automatics. Dust isnt really a problem. Remember, earth has dust too and our guns still fire. Many of our most advanced guns are designed to work in jungles or deserts. And even if the dust is a problem, the heavy simple mechanisms in revolvers would work longer than just about any other gun. Maybe a break-open shotgun would last longer.

I think people are overthinking this. Talk about recoil and such. If the gun (a semi this time) fires once it will chamber the next round unless its designed to require gravity to do so. Usually the guns use the blowback of the previous round firing.

edited 30th Apr '12 11:20:52 AM by Stormthorn

...okay, perhaps I was insufficiently clear. It is blindingly obvious that rockets in general don't require air to function. My impression was that gyrojets specifically had some such requirement, based on airflow or some such thing; I never knew many details of either. I'm not sure how gyrojets do work, and it's entirely possible that they'd function perfectly well on the Moon; I was simply bringing up a possible issue.

I read that the real problem with modern guns in space is that the lubricant would boil, both from the greatly reduced pressure, and from the friction with the bullets. There's also a huge heat management problem in space which normal firearms simply can't solve.

Meh. You can drain an AKM of all its lube, bury it on the Moon, clear the dust out of the barrel and it will fire first time, every time.

Same thing for an M1 Garand. (That's the reason why nearly every part is chrome-lined on the Garand. A beach landing would wash out most if not all the lube you might apply to say nothing of the often wet conditions of the South Pacific where it showed its reputation the best. And still it would fire first time, every time unless you had a bad bullet or a misfeed from the clip. You had to basically corrode the piston and action to non-working state or physically break the thing to keep it from firing in any condition. Just like the AK-47 and derivatives.)

The heat management problem is still real, though. On a wild guess, I'd say you could put one clip through most assault rifles in a vacuum before they'd get too hot to handle safely, and they wouldn't cool particularly fast either.

did not think about heat either, humm, with no air whats going to keep the barrel cool? if you can't cool the barrel how do keep your barrel's life span from being measured in minutes?

The spear guns looking better every day.

Are you sure you're not thinking of a scram jet or something? A self contained rocket engine (which is what a gyrojet is) can be made with self contained fuel.

^^^ Depends on thickness of barrel and air cooling type. A Lewis gun or PKP Pecheneg would work a hell of a lot better in space than an MG-42 because both those guns utilize forced air cooling via increased surface area. In the PKP's case this means it has radiator points all over it. Sure it might be visibly glowing at the end of a 250 round belt but it will cool quicker than most other traditional weapons.

but can you have air cooling with out air?

I think Tom means those guns, or at least the PKP have radiators built into them to help speed cooling. Not sure about the other one though.

edited 1st May '12 5:42:49 AM by Archereon

I looked them up. They use muzzle blast to draw air into the gun to cool it, but that has no effect when there is no air to draw in.

edited 1st May '12 5:53:08 AM by dragonkingofthestars

^^ The PKP's radiators is more I'm referring to. The cooling shroud of the Lewis gun (which is often suspected to have a negligible effect on Earth) is another part of the equation too. While they don't air cool per se, the increased surface area and parts connected to the barrel provide a means of radiating heat away from the barrel while firing.

Sure, and the hotter they get the more efficient radiators are. A gun could probably be designed to radiate away heat fast enough that it wouldn't melt the barrel in space, but none of our current Earth guns are that.