Can Firearms be Fired in Space

[Njal Thorgeirsson]

Wait...so you don't understand why blackbody rates are germane?





There is no reason it would not.

Yes, actually there is a reason it would not- The kinetic energy of the firing pin provides the activation energy to initiate the reaction in which the primer compound decomposes. If the primer is extremely cold, it will take a lot more activation energy (faster strike) to initiate the reaction. Perhaps someone could try chilling a primed (uncharged) cartridge with wart-remover (liquid nitrogen) to <-300F and see if it fires. I'll see if i can find some wart remover and I'll try it next weekend perhaps.

HOWEVER, the member you have quoted is also somewhat incorrect in his analysis. Yes, space is -250F (or as low as -450F depending on source). BUT it is so 'cold' because of a lack of molecular activity (there are far fewer molecules floating around in space than in a concentrated atmosphere). For the most part, a hot object must contact a cold one to transfer heat energy. If there are no molecules bumping into the object (the cartridge), then the object will cool down relatively slowly. Things don't freeze very fast in space. In fact, an artificial vacuum is just as cold as space.

 

[Willie Sutton]

"I just love it when people start talking physics..."


And math...




Willie

 

[Njal Thorgeirsson]

Bonus question: How much mass does a Nosler 55 grain bullet have on the Moon? (trick question alert)

55 grains.

And your answer was very good! Definitely correct physics right here!

 

[Kernel]

In space, in direct sunlight, could a normal everyday primer, the kind we use here on earth, get hot enough to self-ignite?

(That's a lot of commas for one sentence. Hope I did that right.)

it is not germane it's American....

Is that a Wernher von Braun reference? He was German[e] then became an American. Along the way he did something with rockets and space travel.

a dynamite explosion ... would quickly retract back in onto itself

How would it know to retract back to a single point of origin? As noted, vacuum in space is EVERYWHERE. There is no vector.

 

[denton]

55 grains

You have deftly avoided the first snare. But you were caught by the second.

 

[Jim Watson]

If you think I am going to divide 55 by 7000 and then by 32.2 just to show you I know what a slug is, you are nuts.

 

[Njal Thorgeirsson]

You have deftly avoided the first snare. But you were caught by the second.

And what snare would that be? 55 grains is indeed a measure of mass.

 

[Willie Sutton]

^^ What he said. ... it's mass.


"If you think I am going to divide 55 by 7000 and then by 32.2 just to show you I know what a slug is, you are nuts"


Directly from the Department of Redundancy Department? ;-)

Well done.


Willie

.

 

[TEC]

Well, if any of you are of a certain age, and loved the old 1950's TV show "Men into Space", you would have know from childhood that handguns could be and were fired in outer space. And also, you would have known that Angie Dickinson, Col. McCauley's wife in the TV series, was an absolute babe, even to very young guys. You can check out many of the original episodes on You Tube. Can't remember exactly which episodes involved gunplay, but those damned "Ruskies" were involved, as I recall.

http://www.youtube.com/watch?v=ZcKz6uv9Z6w

 

[Carl N. Brown]

Since black powder contains its own oxidizer (KNO[sub]3[/sub] potassium nitrate aka saltpetre) a flintlock should fire in space. I can see it in my mnd's eye: Davy Rocket, Final Frontiersman pre-steam punk sci-fi, black powder powered.

 

[45_auto]

Perhaps someone could try chilling a primed (uncharged) cartridge with wart-remover (liquid nitrogen) to <-300F and see if it fires. I'll see if i can find some wart remover and I'll try it next weekend perhaps.

Back in the late 1990's, I was on a project that was using about 3000 gallons of LN2 (liquid nitrogen) every other day.

After work, we used to fill Dewars (basically big thermos bottles) with it and play with it freezing ballons, cokes, food, etc. I can tell you for a fact that if you soak a crescent wrench in it for awhile, then take it out and immediately use it to pry against a bumper, it will break in half very easily!

We also submerged a couple of dozen 45ACP 230 grain lead round nose cartridges in it for a while, then pulled them out and immediately fired them at steel plates.

The normal room temp lead bullets would give you a disk about the size of a quarter when they flattened out hitting the plates. The cryo-bullets apparently just shattered into powder when they hit, all you could find of them looked like little grains of gray sand. Cases and primers looked perfectly normal.

I wish we had also tried some jacketed bullets to see what they would do.

Anyway, out of the couple of dozen cartridges we cryo-froze and fired, they all worked perfectly.

 

[45_auto]

Dupe

 

[tuj]

The Russians did it.

Almaz was equipped with a unique 23mm Rikhter (factory index 261P or 225P) rapid-fire cannon mounted on the forward belly of the station. This revolver cannon was modified from the tail-gun of the Tu-22 bomber and was capable of a theoretical rate of fire of 1800-2000 (up to 2600) rounds per minute. Each 168 gram (ammo 23-OFZ-D-R ) or 173 gram (ammo 23-OFZ-G-R) projectile flew at a speed of 850 m/s relative to the station. The cannon had supply of 32 rounds and was tested at the end of the mission, when the station was operating in unmanned mode. To aim the cannon, which was on a fixed mounting, the entire station would be turned to face the threat.

 

[denton]

If you think I am going to divide 55 by 7000 and then by 32.2 just to show you I know what a slug is, you are nuts.

LOL.... winner, winner, chicken dinner.

55 grains is indeed a measure of mass

That's not the case. 55 grains is a measure of weight, the force of gravity on a mass.

With a name as eloquent as yours, I'd almost bet the farm that you grew up with a much more sensible system of measures that we usually use here. So rather than converting to slugs, I'd probably just say 3.56 grams.

So you obviously realized that mass is the same, whether you're on the Moon or on Earth, even though the weight is different. A 55 grain bullet has the same mass both places, but grains are the wrong unit of measure for mass.

 

[Quentin]

This really is a fun thread! Neil Armstrong should have tested a 1911 and M16 back in July 1969! Maybe Heinlein's bullet swarm might still be in low orbit today!


Errr... Ben Bova? Men of Good Will?

 

[MattShlock]

...Thankfully, the kinetic energy does not split evenly between the firearm and the bullet... not even close. What is conserved is momentum. For any collection of objects without external forces, momentum is unchanged. The momentum of the bullet, gas, firearm, etc. before ignition = the momentum after.

Hence, if you are stuck in space, having drifted away from your ship, holding a sack of cannon balls, you can propel yourself to the ship by throwing cannon balls away from the ship. Momentum of you and the cannon balls before you throw = momentum of you and the cannon balls after you throw.

This is why a rifle begins to recoil before the bullet exits the barrel. The momentum of the rifle + bullet + gas decrees that as the gas and bullet start to move forward, the rifle will begin to move backward to conserve momentum.

Bonus question: How much mass does a Nosler 55 grain bullet have on the Moon? (trick question alert)

Not! Momentum IS created by converting your dinner into energy. You are using your muscle energy to push off from, applying force against, the canon balls and converting that bio-mechanical energy into linear momentum of your body towards your spaceship.

Can you say "vector moment?" Sure you can.

Creating momentum.

PS: Mass doesn't change in my definition. It is matter-related not defined by gravity. That's MY moon!

 

[DanTheFarmer]

Hey Denton!

I was going to write something similar to you. I knew there are 7000 grains to a pound and that a pound is a unit of weight, not mass; therefore grains are a unit of weight.

When I double checked on Wikipedia it said that the grain was a unit of mass. After reading your comment I double checked the double check with other sources (Britainnica On line)and they say the grain is a unit of weight.

Unless someone puts a good case forward I going with grains being a unit of weight.

We really know how to have a good time on this thread, huh? Party!

Dan

 

[rcmodel]

But?

The OP's only question was, can a firearm be fired in space?

The only correct answer is, Yes, it can.

rc

 

[YZ]

We also submerged a couple of dozen 45ACP 230 grain lead round nose cartridges in it for a while, then pulled them out and immediately fired them at steel plates.

The normal room temp lead bullets would give you a disk about the size of a quarter when they flattened out hitting the plates. The cryo-bullets apparently just shattered into powder when they hit, all you could find of them looked like little grains of gray sand.

An excellent experiment. This beats any speculation.

 

[Malamute]

But?

The OP's only question was, can a firearm be fired in space?

The only correct answer is, Yes, it can.

rc

Yeah, but,..but,..that isnt nearly as much fun as 5 pages of thread drift and discussion.

 

[Black Butte]

Visual proof guns fire in space at 0:17.


http://www.youtube.com/watch?v=uACR_WgOgrw

 

[Jim Watson]

Not! Momentum IS created by converting your dinner into energy. You are using your muscle energy to push off from, applying force against, the canon balls and converting that bio-mechanical energy into linear momentum of your body towards your spaceship.

Can you say "vector moment?" Sure you can.

Creating momentum.

I see it as converting muscular effort/blood sugar oxidative energy into kinetic energy of the cannonball.
Momentum, being a conserved vector quantity, is equal in opposite directions and sums to zero.

Unless you are Aarn Munro with the engine room of the spaceship Sunbeam packed with aggie coils charged with raw momentum.

 

[denton]

Yes, momentum is conserved. Force is not. Kinetic energy is not. Momentum is.

As a further little doodle, momentum=mv. Kinetic energy = [integal] mv =1/2mv^2. Force = [derivative] mv = m dv/dt = ma.

If you want to talk about dinner being converted to kinetic energy, that's valid. Nevertheless, momentum is conserved.

In the cannonball example, if you and your spacecraft are at rest, and you throw cannonballs in the direction opposite the one you want to go, dinner does indeed get converted to kinetic energy. The thrown cannonballs move one way, and you and the sack of remaining cannonballs moves the other. But the center of mass of you and all the cannonballs never moves. For it to move, it would have to be acted on by an external force. F=ma requires that absent that external force, the center of mass doesn't move.

 

[tuj]

The answer is simple. Yes firearms can be fired in space. The Russians actually tested this with their rotary cannon mounted on their space station.

 

[CapnMac]

For the most part, a hot object must contact a cold one to transfer heat energy.

Which is the "why" of the size of the radiators on the ISS.

Which is very much like pouring boiling (100ºC) water into a 98ºC heated pot to "cool" it. Or thawing ice by placing it on a 1ºC plate (sublimation might "win" in that circumstance).

Actually, where the physics would get "interesting" would be upon bodies like Eros or Ceres, or, say moons, such as Mars' Phobos and Deimos--where the gravity is very low. So low as to be functionally "microgravity"--like that experienced on the ISS--despite being several orders of magnitude greater. IIRC, the EV for Ceres is in the 75-150fps range.

Nifty trivia--the ISS is a long ways up there, that ±260 miles into the sky. However, on a 16" diameter desk globe, that's only half an inch or so. For our metric readers, ISS orbits at ±417KM, on a 40.61cm globe that's 13mm--given that ISS is only 78m long, that's about 0.03mm long to scale.

That is, unless I've messed up the calculations from starting with a perverse ratio of 30.32cm = 6371km
Our world here has a very fractal scale--Everest is only a tenth as tall as the ISS--about 5/100" (1.3mm) high on our putative globe; Challenger Deep in the Marianas Trench would be a bit more than 0.07" (1.77mm) deep.