Martian Firearms?

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ACIinventor

ACIinventor

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NASA's Ingenuity helicopter has successfully completed a second flight on Mars. - Brought to mind a an idea for a new thread: How would firearms function differently on the surface of Mars?
This might be an interesting exercise in understanding basic fundamentals about firearm ballistics.
Here are some questions to ponder.
1 What would be the 'Standard Atmospheric Model' for ballistic tables on Mars?
Earth's Standard Atmospheric Model:
Altitude: Sea level
Barometric pressure: 750mm Hg-29.53 inches Hg
Temperature: 59 degrees F
Relative humidity: 78 percent
2 Could temperature-insensitive powders be made to handle the colder Martian temperatures?
Mars average temperature: -80 degrees F
Summer at the Martian equator: 70 degrees F (day) & -100 degrees F (night)
Winter near the poles: -195 degrees F
3 Would suppressors ever be needed on Mars?
Mars atmosphere 1% the density of Earth's
95% carbon dioxide, 2.6% nitrogen, 1.9% argon, .16% oxygen, and .06% carbon monoxide

Feel free to add additional questions to this thread...
 
Hugger-4641 said:
Well, the first problem is that there is not enough Oxygen on Mars. So unless a special cartridge was made with its own oxygen supply, I don't think you get enough powder burn to push the bullet out of the barrel.
Click to expand...

That's been discussed before. Powder doesn't need outside oxygen to burn. It contains its own.
Otherwise it wouldn't do so much from an enclosed case that forms a seal by design.
 
DukeConnor said:
First thing that popped into my mind.

I seem to recall that there was a study on this subject quite awhile ago that proved a firearm could still operate in space or low oxygen situations. The premise was proven by shooting under water (?)
Click to expand...

Yeah, I could see the water helping to create a seal, but being under vacuum is a different matter. Mars atmosphere is basically a vacuum compared to Earths.
 
Hugger-4641 said:
Yeah, I don't buy that. If oil can seep in to a cartridge and ruin it, which I have seen, then I don't think the Oxygen stays in the "sealed" cartridge for very long.
Click to expand...

Well, cartridges seal a lot better under firing pressure.
But they don't contain their own oxygen because it's sealed in the case. It's the powder itself. As long as it's uncontaminated and gets a primer, it goes off.
 
The first question is what the firearms would be used for on Mars, that would justify the cost and effort of getting them there?

Once we get past that question, then we need to realize that analysis of the Martian atmosphere and temperature in comparison to that of Earth, for ballistic purposes, is largely irrelevant. That is because all human activity on Mars would have to take place in a controlled environment, or "bubble," that replicated conditions on Earth. Humans could not survive, unprotected, on the Martian surface. So any shooting would have to take place indoors in the protected "colonies." Gravity would be a ballistic factor, but atmosphere and temperature would not.
 
AlexanderA said:
The first question is what the firearms would be used for on Mars, that would justify the cost and effort of getting them there?
Click to expand...

Well, until people live up there and Red Faction kicks off (in which sledgehammers would apparently be more popular, anyway), I figure it would more likely be things like location marking (launching a marker or flare up a grade or down a cliff instead of treking down there) or active seismic sensors.

Normal 'what if' speculation aside, of course.
 
Oxygen isn't required for ignition, the powder isn't burning by oxidation, but releasing stored nitrogen, and chemically converting it by heat to product nitrogen gas from solid compounds. The heat is provided by the primer. Ammunition would work fine in zero oxygen. The shot would be quieter by far, and recoil would push you more, but not kick any harder. The bullet would travel much farther, and flatter, but higher than point of aim due to gravity and reduced resistance.
 
The standard Martian firearm uses a suitable propellant to fire a glassy projectile to great range. Upon impact, the glass fractures, exposing the radium core to unfiltered daylight which causes it to explode. The morning after any night action, the battleground is covered with spent projectiles exploding when illuminated by sunrise.

If you disagree, you may take it up with the Edgar Rice Burroughs estate which will refer you to John Carter the next time he is on Jasoom, known by the natives as Earth.
 
Gun powder is a mixture of fuel and oxidizer and does not require external oxygen to work. Same for primers. Gun powder will burn in a pure vacuum assuming it is in close volume to allow it to build pressure. It needs pressure to keep the flame front propagating into the powder grain.

The martian surface atmosphere is about as dense as earth's atmosphere is at an altitude of 22 miles. Due to the lower gravity and lower density atmosphere, surface pressure is only ~0.6% of earth's surface pressure.

In a practical sense shooting on Mars would be similar to earth but with atmospheric conditions and the low gravity, bullet trajectories would be much flatter and retain velocity/energy down range better than on earth. Sighting a rifle with a space helmet on would suck, I have shot in full face helmets before and check welds are not practical.
 
Hugger-4641 said:
Yeah, I could see the water helping to create a seal, but being under vacuum is a different matter. Mars atmosphere is basically a vacuum compared to Earths.
Click to expand...

is there a vacuum in space or is there just a lack of atmospheric pressure ?

I'm sure we could just google it but I enjoy the speculation.

MCB answered it while I was typing. So no vacuum.
 
mcb said:
Gun powder is a mixture of fuel and oxidizer and does not require external oxygen to work.
Click to expand...

Well, black powder is.
Smokeless powder is one or two unstable compounds tha deflagrate when initiated, no separate oxidizer involved.


Gun powder will burn in a pure vacuum assuming it is in close volume to allow it to build pressure. It needs pressure to keep the flame front propagating into the powder grain.
Click to expand...

Yes, but the cartridge, chamber, and barrel are ample confinement to build that pressure. The difference between 14.7 psi atmospheric pressure and a vacuum is a lot less than the natural variability of propellant pressure, it isn't confining much with 15,000 to 50,000 psi inside.
 
"Barsoom," I think?

ETA: Oops, you're right. Barsoom was the name for Mars.

Jim Watson said:
The standard Martian firearm uses a suitable propellant to fire a glassy projectile to great range. Upon impact, the glass fractures, exposing the radium core to unfiltered daylight which causes it to explode. The morning after any night action, the battleground is covered with spent projectiles exploding when illuminated by sunrise.

If you disagree, you may take it up with the Edgar Rice Burroughs estate which will refer you to John Carter the next time he is on Jasoom, known by the natives as Earth.
Click to expand...
 
Jim Watson said:
Well, black powder is.
Smokeless powder is one or two unstable compounds tha deflagrate when initiated, no separate oxidizer involved.




Yes, but the cartridge, chamber, and barrel are ample confinement to build that pressure. The difference between 14.7 psi atmospheric pressure and a vacuum is a lot less than the natural variability of propellant pressure, it isn't confining much with 15,000 to 50,000 psi inside.
Click to expand...

Those unstable nitrates that are part of the nitrocellulose and nitroglycerin in smokeless propellant are also oxygen sources. Those NO3 groups come off the larger molecule releasing allot of energy and in that elevated temperature/pressure of the deflagration further break down into NO & NO2 giving up oxygen to the reaction to allow some of the other byproducts to combust.
 
Yes, but it is still not a mixture, it is one or two chemical compounds you cannot separate into fuel and oxidizer.

Inorganic oxidizers are inefficient, black powder is 75% potassium nitrate, ANFO blasting agent is 94% ammonium nitrate.
 
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