9mm VS 45ACP for Shooting in Outer Space?

[Kind of Blued]

This statement reveals a complete lack of knowledge about radiation cooling a hot object in a vacuum.
There is NOTHING needed to carry the heat away.
It is electromagnetic radiation.

Or are you still looking for the 'ether' the Michelson & Morely showed did NOT exist?

I agree with Gun Slinger, you are something of a condescending jerk.

Please try harder to be polite, or stop posting on my thread.

 

[benEzra]

Radiative cooling is VERY significant given that the thermal background (if the object is in shadow) is very cold indeed, and the heat flux is proportional to the fourth power of the absolute temperature. Meaning, as your barrel temps climb above 350 degrees fahrenheit or so, your gun will be shedding heat furiously, particularly if you roughen the surface to increase surface area and paint it black to increase the emissivity. A black painted gun might shed ten times the heat at any given temperature as a polished stainless gun would.

 

[-v-]

But, would the radiative cooling be sufficiently fast as to keep barrel temperatures in the green with a conservative rate of fire of 200 rounds per minute on a handgun?

 

[icebones]

i woundnt worry about sealing the barrel, the chimical formual for modern smokeless powder has oxygen

most moder smokeless powder is either nitrocellulose, mixed with either nirtoglycerin or nitroguanidine. oxygen is already present in the chemical composistion of powder,
the only thing i would be worried about in space is the temperature extremes.

im not an astronaught, but isnt space either freezing cold in the shadows, and boiling hot in the sunlight?

also, a 9mm would be theroetically better in space. less recoil, higher velocity.

heck a .17 hmr would be the best. it doent matter where you hit the intended target. that bullet will tear through the space suit and the vacuume of space will kill him faster than any bullet.

also because ther is no air in space, the barrel of said gun wouldnt need to be rifled...

 

[brickeyee]

"agree with Gun Slinger, you are something of a condescending jerk.

Please try harder to be polite, or stop posting on my thread."

Cause gunslinger is clueless?

You own the thread?

Condescending to point out a wholly inaccurate statement?
Gunslinger is just WRONG.
Maybe he should grow up and realize that.

This from somone who started off with:

But no, really, I've never thought about shooting a gun in outer space until I made a joke about it. The barrel would have to be sealed to the muzzle and filled with air so that the powder can burn until the bullet exits the muzzle. I would think powder would not burn properly.

 

[fearless leader]

Neither

This is pointless! The TSA won't allow you to take anything like that into space.

You are aware you can fire guns underwater, aren't you? If you could fire them underwater, I don't think space would be that different.

http://youtube.com/results?search_query=Glock+19+underwater&search_type=

Your shot will probably be high, because sights are calibrated to allow for a rise and fall trajectory, but in space, your trajectory is virtually flat unless near some large gravitational pull.

Recoil would be under Newton's law of Motion: an object in motion tends to remain in motion until something stops it.

Every action has an equal and opposite reaction.
The act of propelling a projectile with X foot pounds of energy will result in an opposite reaction of X foot pounds of energy, having some expended on the slide recoiling, which still recoils against your hand.

Good luck getting an Inter Planetary CCW permit!

 

[madmike]

icebones: as has been discussed, space is NOTHING. In sunlight, an item will absorb heat. In shadow, it will radiate it. However, this also applies to the user. I could complain that a pistol won't work in a volcano...however, since I won't either, it's not a big consideration The pistol will work anywhere I can (given current spacesuit tech).

A pistol wouldn't work as propulsion on the Moon, and would be lousy propulsion in space. I imagine the purpose in having one was sovereignty and tradition--the commander ALWAYS has a pistol, security for the landing site if something went wrong, and in case of the remote chance of an attack.

The additional velocity of a 9mm isn't needed. The smaller cross section MIGHT make for a better penetration under some circumstances. I've never found 9mm to be lighter in felt recoil. It's sharper and more of a sting. However, as recoil weight is a function of energy, that does mean a less powerful round. I concur on .22 mag or .17.

-v-: I think 200 rounds a minute is not "conservative" but insane. How many space-suited zombies are you shooting at??

Rifling is still a good idea against irregularities in the propellant burn and mass variations in the projectile.

 

[Gun Slinger]

Originally posted by brickeyee:
"agree with Gun Slinger, you are something of a condescending jerk.

Please try harder to be polite, or stop posting on my thread."

Cause gunslinger is clueless?

You own the thread?

Condescending to point out a wholly inaccurate statement?
Gunslinger is just WRONG.
Maybe he should grow up and realize that

This from somone who started off with:

But no, really, I've never thought about shooting a gun in outer space until I made a joke about it. The barrel would have to be sealed to the muzzle and filled with air so that the powder can burn until the bullet exits the muzzle. I would think powder would not burn properly.

Wow.

Lots of "angst" going on there, brickeyee.

If you are "on" medication, stay with it, things will get better. If you are "off" of it, get back "on" it, perhaps it'll "help".

You are, indeed, correct. I am "wrong". Condescension was the incorrect term to use. Actually you are rather offensive. The only 'point' that you have actually 'made' is that you are cantankerous and lacking in appropriate social skills and would do well to address these "issues".

Again, I wish you the best of luck in dealing with this COLOSSAL TASK.

Perhaps the Moderators could look into closing this thread since it seems to be a "source of aggravation":banghead: for 'brickeyee'.

 

[benEzra]

Every action has an equal and opposite reaction.
The act of propelling a projectile with X foot pounds of energy will result in an opposite reaction of X foot pounds of energy, having some expended on the slide recoiling, which still recoils against your hand.

You are correct, but the quantity that is symmetrical in action-reaction pairs isn't kinetic energy, it is momentum. The forward momentum of a bullet + combustion products equals the rearward momentum of the gun and the shooter. The bullet carries a lot more kinetic energy than the recoil does, though (because KE goes as the square of the velocity, and the bullet velocity is immensely higher than the recoil velocity).

 

[brickeyee]

It does not bother me.

Perhaps after claiming you understand radiative cooling but failing to understand no medium is required for electromagnetic radiation you should just go back to class.

"It is better to be thought a fool, than to open your mouth and remove all doubt."

 

[Gun Slinger]

brickeyee,

In regards to your last post:

Originally posted by brickeye:
"Perhaps after claiming you understand radiative cooling but failing to understand no medium is required for electromagnetic radiation you should just go back to class."

I have never made such a claim. The statement quoted by you and attributed erroneously to me by you at the top of this page (post #101) comes from post #72 on page 3 of this thread and was made by someone else.

Space is mostly empty, and heat needs something to carry it away.

If you'll be so kind as to check the posts that I have made within this thread, never have I made the statement or expressed that a medium is required for the transfer or conveyance of electromagnetic radiation. Please refer to all posts made by me: #78, #80, #85, #87, #89, #97, and #109.

Since I have grown tired of your unjustified and insulting behavior, I am finished with you for the duration and will no longer be posting on this thread in response to your rude and abusive posts. I take the 'high road' here and now and leave you to do whatever you will. The Site Moderators have been informed of your atrocious conduct and can deal with you as they see fit from here on out.

 

[icebones]

heres something else to think about...

what about firing a gun on a planets surface?

like on the moon or on mars?

 

[icebones]

hows about some soft of gyroscopic stabilizer to prevent you from flying backwards upon firing?

 

[Kind of Blued]

brickeyee, I don't care who was right. I called you condescending because you are not politely informing people, rather telling people that they are wrong and exhibiting no manners or any sign of post-adolescent social skills. I hope you can figure that problem out and relax a bit, for your own sake.

 

[Funderb]

In outer space, you don't have to worry about distance to target and bullet drop. I go for the biggest piece of lead.

 

[Funderb]

I don't know if you have heard of a thermos, brickeyee.
"Keeps hot things hot, and cold things cold, but how does is know?!"


Heat does not magically radiate into a vacuum, the LCE applies in space too. It simply is absorbed into the gun, and the gases that surround you in space, and are very good at stealing heat because they have been cooled for thousands of years. It's not a perfect vacuum you know.

And, oh, heat is THERMAL radiation. not electromagnetic.

 

[Huddog]

Not even interested, since it is impossible. Besides by the time we are fighting in space it'll be with phasers and ray guns.

 

[madmike]

Not even interested, since it is impossible. Besides by the time we are fighting in space it'll be with phasers and ray guns.

That turns out not to be the case.

Even good solid state lasers are below 20% efficiency. (I may be wrong, but I think that's the last I recall. I can ask my father in law who is something of an expert.) There are experiments around 65%. Still.

500 foot pound = 0.1883 watt hour

or 6800 watts for .1 seconds, at 65% efficiency = 10 kilowatts of energy per shot. Going to carry a large electric generator with you? And a cooling source? You'll need a LOT more than just radiator vanes to waste that much energy.

The problem is, the energy has to be created somewhere. Unless you carry a nuclear reactor in a backpack (Possible, but, very heavy), chemical reactions are where the power comes from. You can use that reaction to move pistons up and down, turn a crank, turn a rotor, each with a resultant loss of efficiency...

Or you can just make the piston out of lead and THROW THE THING OUT THE CYLINDER DIRECTLY. That's technically called a "Bullet.";-)

Sometimes the brute force approach IS best.

Since a phaser was just a fancy way of saying "laser" but sounding cool, forget that.

Something like Drake's powerguns may be possible, but that's not even theoretical at this point, and still has the problem of MASSIVE heat to be radiated.

 

[hso]

Well this went from silly to ugly, and a bit tragic.

Please take note: It wouldn't hurt anyone to pick up a copy of Halliday, Resnick, Walker: Fundamentals of Physics, 6th Edition and spend a little time with it.

Done.