Will a gun fire in space?

[Muddy_Ford]

I vote NO. Because it would be kinda hard for you to get your booger hook on the bang switch with those huge gloves you have to wear in space, however, were it not for that insignificant fact I believe the gun would fire based on some of what I've read in this thread.

 

[rhino]

You make good points, li'l brother.

My intuition tells me that the low temp probably won't prevent the combustion of the propellant. If the primer can make a spark, that should be enough energy to initiate the reaction and once it starts, it's going to finish.

Whether or not the primer will ignite and make that spark could be the stickier of the two wickets. I would bet that it will, though.

How much energy is necessary to activate the primer compound and is it temperate-dependent?

Standard pressure is 100 kPa or 14.504 psi. (This is the pressure for "standard conditions" on Earth. Typically what we experience.)

SAAMI Pressure for 9mm +P is 265,450 kPa or 38,500 psi.

So the difference between the inside of the barrel and the outside is 265,550 kPa or 38,514.504 psi in a perfect vacuum of space.

The gun will barely feel the difference. In fact there is more variation in that with typical inaccuracies of powder volume in most rounds.

The round is completely sealed before and during the firing from atmospheric oxygen, so all combustion will happen the same way with one possible problem: Temperature.

Temperature in space is around 2.725 Kelvin. This is around -270 C or -455 F. So without solar radiation, the firearm will be cold enough to potentially not allow the primer to ignite the powder. Also, there may be low temperature metallurgy issues that cause problems at that low of a temperature. There will more than likely be issue with polymer parts.

My Glock MAY Kaboom, in a non-humor sense. It would be the grip failing, even if the barrel and slide did not fatigue. I have not looked at the temperature range of the polymer that Glock or others use for the plastic pistols.

Now, lets get to another problem. How much do you lubricate your gun before you go into space? You did use dry lubrication so the grease and oil isn't frozen, right? -455 F is COLD. Otherwise, you will get a jam after the first shot, because the slide isn't going anywhere.

Anyhow, that's all I got. Because of the temperature issue, my answer has to be a probably or most likely.

 

[CandRFan]

I vote NO. Because it would be kinda hard for you to get your booger hook on the bang switch with those huge gloves you have to wear in space, however, were it not for that insignificant fact I believe the gun would fire based on some of what I've read in this thread.

Well, what if the gun were a Type 14 WITH the larger 1939 trigger guard?

 

[hookedonjeep]

mmmmmm...... bacon. Great, now I have to go fry some up......

 

[Mr. Habib]

You make good points, li'l brother.

My intuition tells me that the low temp probably won't prevent the combustion of the propellant. If the primer can make a spark, that should be enough energy to initiate the reaction and once it starts, it's going to finish.

Whether or not the primer will ignite and make that spark could be the stickier of the two wickets. I would bet that it will, though.

How much energy is necessary to activate the primer compound and is it temperate-dependent?

The military test small arms to -40F. They run into problems even at those temps. Low temp reliability is the reason that Comm Block ammo is still loaded with corrosive primers, BTW. The military also see chamber pressures and velocities drop off at low temps. In space the temperature is approaching -454F. If the primers are beginning to have ignition issues at -40F, they will completely dead long before reaching -454F.

 

[jbombelli]

The thing is, there's virtually no convection or conduction in outer space. There are no molecules to bump into an object and transfer heat. We are left with only radiation as a form of heat transfer. Objects in a virtual vacuum cool down very slowly, if I remember my physics from nearly 30 years ago right. Objects that start warm will stay warm for a long time in space. This is why it takes asteroids millions upon millions of years to cool down, and you end up with Windmanstatten Patterns in them.

Plus, if the gun is exposed to the sun, it will likely get very hot, and maybe just cook off on its own.



Again, if I remember my HS physics right.

Which is questionable.

 

[ATM]

I, of course, voted for Bacon.

 

[PhantomJ]

You reloaders need to get to work, if you can get a bullet up to (escape or critical speed (ve) = 5348.4363543509 foot/second)
it will leave Earth orbit and travel the stars, or at least the Solar system. Assuming standard shuttle orbit distance of ~300 Km.


edited to add I don't know of a standard round that can achieve that velocity.

 

[MACHINEGUN]

 

[DeadeyeChrista'sdad]

Alright, which one of you wise guys launched that test missile the other day? I'm all for creative science and all....

 

[rhino]

Radiation heat transfer is proportional to temperatures ^ 4th power. The heat from a room temp gun is going to radiate at a high rate to space, unless the sun is shining on it (as you mentioned). Then you'd have to consider the net rate of heat transfer (whether it's into or out of the gun). It would depend.

The thing is, there's virtually no convection or conduction in outer space. There are no molecules to bump into an object and transfer heat. We are left with only radiation as a form of heat transfer. Objects in a virtual vacuum cool down very slowly, if I remember my physics from nearly 30 years ago right. Objects that start warm will stay warm for a long time in space. This is why it takes asteroids millions upon millions of years to cool down, and you end up with Windmanstatten Patterns in them.

Plus, if the gun is exposed to the sun, it will likely get very hot, and maybe just cook off on its own.



Again, if I remember my HS physics right.

Which is questionable.

 

[indyjoe]

Radiation heat transfer is proportional to temperatures ^ 4th power. The heat from a room temp gun is going to radiate at a high rate to space, unless the sun is shining on it (as you mentioned). Then you'd have to consider the net rate of heat transfer (whether it's into or out of the gun). It would depend.

Stefan-Boltzmann Law. It has been a LONG time since I took Thermodynamics. Lets see if I can remember anything. Lets assume no solar radiation is falling on the gun and see what happens.

q = c T^4 A (assuming emissivity of 1 or "perfect")

q = heat transfer per unit time (in Watts)

c = Stefan-Boltzmann constant 5.6703 x 10^-8 (W/m^2K^4)

T = temperature in Kelvin

A = area of the emitting body

Figure the Area of a Glock 19 slide. 17.4 cm long Say 2x3cm cross section.

So A in meters is 2*0.174*0.02 + 2*0.174*0.03 = 0.0174 m^2

Start it out at room temp of 70 F? (70 + 459.67) * 5/9 K = 294.2611 K Lets call it 294 K.

q = 5.6703 x 10^-8 (W/m^2K^4) * 294^4 K^4 * 0.0174 m^2

q = 7.37 W or 7.37 J/sec.

It is not too fast at room temperature and exponentially slows as the temp gets closer to absolute zero.

Heat Capacity of Steel (Cp) is around 0.5 kJ/kg K So it takes 0.5 kJ radiation to reduce 1 kg of steel by 1 K (or 1 Celcius).

Not sure of the weight of a Glock slide. Say 2.2 pounds? -> 1 kg.

So we are cooling at a rate of 7.37 J/sec and falling, and it takes 500 J to reduce the temperature of the slide by 1 K. 67.8 second for 1 K drop.

Yeah. It would take that pistol a while to cool off to space temps. Firing one shot would heat it up considerably. I'm now of the opinion that over heating would be a real concern with repeated firing, due to the serious lack conductive cooling.

Hope my math is right.

And this eliminates my reservation of Temperature for any weapon that is brought with the astronaut. I would fire fine for a LONG time.

 

[Larryjr]

I have nothing to base my answer on but it seems to me the cartridge would be independent of its surroundings so it should fire when struck.

 

[rhino]

Heat Capacity of Steel (Cp) is around 0.5 kJ/kg K So it takes 0.5 kJ radiation to reduce 1 kg of steel by 1 K (or 1 Celcius).

Not sure of the weight of a Glock slide. Say 2.2 pounds? -> 1 kg.

Your analysis is excellent ...

You've convinced me that it would take a significant time to cool. I forgot how tiny the S-B constant was, so that offsets the temp^4. All I was thinking of was the temp^4 part.

I also did a double take on the heat capacity, then I looked again and realized you're using joules and not calories. I've been programmed to use calories for heat calculations the last three years!

You have shamed me into submission, Mr. S.

 

[Bondhead88]

I don't care as long as there are no terrorists in space I just want Bacon!

 

[bman1962]

Bacon for sure!!!

 

[machete]

Yes it will, the bullet will go straighter and faster also.

so in space,,,a .45-70 and a .50 BMG have the same ballistic trajectory???

COO-OOL!!!

 

[CGS]

My opinion is that a gun will fire in space since the explosion is contained and relases the gasses which propells the bullet. Therefore the theory is no different than the jet propulsion of the rockets and space shuttles.

 

[JordanN]

Have you never heard of a solid fuel rocket? Of course a modern sealed-cartridge firearm will operate just fine in space.

 

[longbow]

My physics training says yes, but you will need full auto to correct your course in orbit. Just another reason full auto should be for everyone.....