Martian Firearms?

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GEM said:
Battlestar Galactica used The FN Five-seveN® FDE pistol for service arms and that 4 barrel COP for concealed carry.
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Actually that's an interesting thought. Since the weight would be at a premium and mars is lethal enough that damaging a suit would probably be sufficient to get the job done. If the CIA or whatever decided that they needed to get a square jawed all american operator to mars would they try to get away with something small bored like the 5.7?

Better question can we do it anyway and see if we can get cheap surplus martian 5.7 ammo?
 
Wasn’t convinced of the so-called moon “landings” when I saw it on TV back in ‘69.

Also not convinced that Mars exists either, much less that we have been there. Call be old and crotchety but according to me there is only one planet and it’s the one we are standing on right now.
 
theotherwaldo said:
One more point - Ammunition that was assembled within an Earth-pressure atmosphere should disassemble itself when exposed to near vacuum because of the high-pressure air within the cartridge, which would be approximately the pressure of the air in a car tire relative to the Martian atmosphere... .
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14.7 psi inside a tiny cylinder isn't remotely comparable to the air inside a car tire. Don't forget to take into account the relative mass of the air as well, that would be a factor too.
 
Mythbusters proved that a vacuum has very little affect on ammunition performance.

I would hazzard a guess that powder temperature would have more influence than atmospheric pressure.
 
GEM said:
The more important question is whether you make your own reloads on Mars as the weights would be off. You would have to re-calibrate everything!
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Not if you use a conventional reloading ‘scale’ because it’s really a balance and not a true scale. The lower gravity would affect the sliding weights and the powder charge the same, giving the same results as on earth.


JCooperfan1911 said:
Exactly,
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Exactly wrong.

JCooperfan1911 said:
Wasn’t convinced of the so-called moon “landings” when I saw it on TV back in ‘69.

Also not convinced that Mars exists either, much less that we have been there. Call be old and crotchety but according to me there is only one planet and it’s the one we are standing on right now.
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You can see Mars through a sub-$100 telescope. Ancient peoples observed its movement across the sky relative to the stars for thousands of years. You might want to consider going outside more.
 
This is a fun thread. Would electronic balances be affected gravity? I have no idea. I used them in chemistry lab back in college. It was funny as we had to learn how to use the old beam balances and weight sets. I asked the prof why we were wasting our time with them. He said, what if civilization failed and there was no electricity. I said - well, I'd better off learning how to grow corn.

Now debating whether the moon landing and Mars exists is a waste of time as that post is either a joke or a sign of pathology. So let's skip that for both reasons.
 
GEM said:
This is a fun thread. Would electronic balances be affected gravity? I have no idea. I used them in chemistry lab back in college. It was funny as we had to learn how to use the old beam balances and weight sets. I asked the prof why we were wasting our time with them. He said, what if civilization failed and there was no electricity. I said - well, I'd better off learning how to grow corn.

Now debating whether the moon landing and Mars exists is a waste of time as that post is either a joke or a sign of pathology. So let's skip that for both reasons.
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A digital Earth scale that uses a force sensor to weight something would be correct for weight (lbs or Newtons) but would be incorrect for mass (slugs or kg). The problem is we have confounded the two different but related properties, mass and weight, in the US education system so badly and with our unit systems that it is very confusing for many. Most of our US scales report a force of lbs when weighing something in US customary units and yet if you switch units on the scale to SI (metric) you will get a reading in mass of kilogram or grams typically. None the less, the mass would be wrong on Mars since the scale is measuring a force produce by and object mass under gravitational acceleration and converting that to a mass by dividing my an assumed gravitation acceleration of earth 32.17 ft/sec^2 (9.81 m/sec^2). You could correct the number by dividing the mass readout by the ratio of the surface gravity acceleration of the planet the scale was designed for by the surface gravitation acceleration of the planet your using the scale on. In the Earth scale on Mars case this would be 2.64 (9.81/3.71).
 
mcb said:
A digital Earth scale that uses a force sensor to weight something would be correct for weight (lbs or Newtons) but would be incorrect for mass (slugs or kg). The problem is we have confounded the two different but related properties, mass and weight, in the US education system so badly and with our unit systems that it is very confusing for many. Most of our US scales report a force of lbs when weighing something in US customary units and yet if you switch units on the scale to SI (metric) you will get a reading in mass of kilogram or grams typically. None the less, the mass would be wrong on Mars since the scale is measuring a force produce by and object mass under gravitational acceleration and converting that to a mass by dividing my an assumed gravitation acceleration of earth 32.17 ft/sec^2 (9.81 m/sec^2). You could correct the number by dividing the mass readout by the ratio of the surface gravity acceleration of the planet the scale was designed for by the surface gravitation acceleration of the planet your using the scale on. In the Earth scale on Mars case this would be 2.64 (9.81/3.71).
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This is a good explanation. The problem is compounded by the fact that on Earth (at least at sea level) mass and weight were set up to be interchangeable. Whenever you ‘weigh’ a powder charge using a balance you are actually measuring the equivalent mass and since both sides of the balance are pulled equally by the gravity it gives you a correct result. A true scale, like a spring scale would give you a weight, but unless it had been calibrated for Mars gravity it would give you an incorrect reading because what it really measures is how far the spring is being stretched, and the lower gravity won’t stretch it as far.

I used to tell my students to remember that balances measure mass and scales measure weight. I never said “weigh” materials, I always said “take the mass of ...”

It doesn’t help the confusion when what popular culture depicts as the “scales of justice” is actually a balance.
 
GEM said:
This is a fun thread. Would electronic balances be affected gravity? I have no idea. I used them in chemistry lab back in college. It was funny as we had to learn how to use the old beam balances and weight sets. I asked the prof why we were wasting our time with them. He said, what if civilization failed and there was no electricity. I said - well, I'd better off learning how to grow corn.

Now debating whether the moon landing and Mars exists is a waste of time as that post is either a joke or a sign of pathology. So let's skip that for both reasons.
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The USSR would have called BS on the US if it didn't happen. :evil:
 
They used to sell a small torch assembly that used the small tanks of propane combined with a solid stick of a chemical mixer that gave off oxygen when ignited. For those who doubt that gun powder does not need external oxygen to combust, how do you explain the generation of oxygen from a solid stick of blended material when it is put to a smoldering condition.
 
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.
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Modern ammo contains all the oxygen it needs, ever seen video of guns being firing underwater?
 
Mechanical problems in early satellites were sometimes attributed to cold welding.

In 2009 the European Space Agency published a peer reviewed paper detailing why cold welding is a significant issue that spacecraft designers need to carefully consider. The paper also cites a documented example from 1991 with the Galileo spacecraft high-gain antenna.

One source of difficulty is that cold welding does not exclude relative motion between the surfaces that are to be joined. This allows the broadly defined notions of galling, fretting, sticking, stiction and adhesion to overlap in some instances. For example, it is possible for a joint to be the result of both cold (or "vacuum") welding and galling (or fretting or impact). Galling and cold welding, therefore, are not mutually exclusive.

Vacuum welding?
 
JohnKSa said:
According to this source, it would take over 5600 meters/second to get into a 250km elliptical orbit around Mars.

https://marsbase.org/section10#:~:text=Ascent Propellant Estimate&text=The ∆v from Mars,HEMO is 5625 m/s.

That's over 3x faster than the fastest firearm muzzle velocity I'm aware of.
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But the question then is, how much does relative atmospheric density effect muzzle velocity? I assume the bullet wouldn't be THAT much faster coming out of the case on Mars, but there should be some increase, as it's not fighting as much pressure in the barrel.
 
Muzzle velocity would be very similar because even on earth, the atmospheric pressure is many thousands of times smaller than the pressure pushing the bullet. Once out of the barrel there would be a significant difference due to the air being so much thinner. The bullet wouldn't slow down nearly as fast. But it would still slow down some because there is atmosphere--just not as much. The muzzle velocity would have to be enough higher than the required delta v to insure that atmospheric friction didn't drop the bullet speed too low to achieve orbit before it got out of the atmosphere.
 
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