We all know you can fire a gun in space, but would a gas operated self loader like an AR or AK cycle in a vacuum?
Wouldn't that mean revolvers and pump/lever actions are the best guns for spess?
>We all know you can fire a gun in space, but would a gas operated self loader like an AR or AK cycle in a vacuum?
Yes. The gas is provided by the cartrige; the propellant.
They would cycle like anything else.
>space has an average temperature of -450°F, i don't see overheated guns being an issue
Space may be cold, but once you've got heat, it is almost impossible to get rid of it because there is no air to absorb it. A gun will melt its barrel after only a few shots.
How can empty space even have a temperature?
The only method of heat transfer for an object in space is radiation, unless its in contact with the holder but the small amount of conduction will do little to the rapidly increasing stored energy.
Revolvers are probably better because you don't want spent cartriadges flying around the ship/station. Hot brass messing with oxygen bottles, computers and all the delicate equipment would ruin your day.
>cant tell if serious or trolling
>the freezing temperature of space should keep the water from heating up too much.
Do you think water instantly freezes in space or something? They've found entire clouds of liquid water in space. Literally trillions of gallons of unfrozen water, just floating around in space.
Guns would need a similar heat-management system as a space suit or forget about firing in burst or automatic.
Look how many radiators the ISS needs for probably a single story office building worth of working space and computers. Look up how complicated they are if you think they're just big things filled with water.
as >>28592640 said, the largest problem in space is heat dissipation
a normal handgun might also experience cold welding
and you would NEVER be able to move yourself with any rifle or handgun, because in space you still have mass, a full magazine from a M16 would impact the most minimal of motion to you
>minimal of motion
that might be true enough, but unless you put the line of fire exactly in line with your center of mass, you're going to be spinning like a set of cheap rims on a ricer.
Pretty sure it wouldn't because any non 100% sealed piston system would have the gas quickly escape out of gas ports
A G3 might work as they have no gas system, just delayed blowback
(bullet momentum 4 kg m/s, fired from 40 cm from the center of the axis, the angular momentum imparted to the marksman is thus 1.6 kg m2/s. Divide that by marksman's moment of inertia, and you get an angular speed of 0.05 rad/s, or less than 3 deg/s.)
i was wrong about the rate of spin, the math is from rocket rho
Oh god. In space, where a long gun really finally isn't cumbersome, they decide to make it so far behind over the shoulder that the backpack unit gets in the way. Now this is sci-fi for the looks only, alright.
>temperature in space
>anything like Earth
If it was like that at all, the gun would have a new problem. The temperature of -450f would have a serious issue with the metal parts being that cold and then having the heat of the miniature explosions having such as massive difference in temp.
Damnit guys, having a surrounding temperature of ~2K is going to make for some serious radiative heat dissipation, particularly when you're getting upwards of 200C. Radiative cooling is driven by the temperature difference to the 4th power.
No they are not.
They are irrelevant in the sense of 10^-3 bar vs. 10^-9 bar or something along those lines. However, space most definitely has a temperature, and it's fucking cold. We put insulation in spaceships for a reason. Heat will dissipate, just very slowly.
Now the correct point being made here is that thermal energy has to transfer through something. Space being a near vacuum allows for very minimal heat transfer. You need to use radiator vanes for most things (like an RTG) to dissipate waste heat. And the dissipation is fucking slow compared to a heat sink with vanes somewhere with an atmosphere.
A gun barrel would heat continually based on the thermal capacity of the steel. I have no idea how many shots could be fired, but it would heart to melting before too long. The cool down period would be lengthy.
Okay, each bullet is 3 degrees per second. That would make a magazine from a G19 give you ~45 degrees per second, which while not quite amusement park levels of speed would be enough to fuck your day up trying to actually do anything
Transfer the heat into a fluid, then venting that fluid when it changes phase. Your spess vehicle will need thrusters to orient anyway, use the tanks of liquid nitrogen as your heat sink. This will obviously only really work for vehicle based weaponry, but it would work.
Yes, with a few assumptions.
An AR at sea level for 100kpa versus an AR in vacuum is a difference negligible with respect to the ~400,000kpa between a fired .223 cartridge and its projectile.
Radiative cooling kinda sucks ass so you will need to fire as little as possible and want to use as heavy a bull barrel as possible. This is hardly exclusive to self loading firearms, though.
I think most people don't understand how heat loss here on Earth works, let alone in space.
Let's just say that most heat lost is in the same way sound moves, it spreads from matter to matter. Remove ambient matter, ie be in space, and you have alot less heat loss. Yeah this is very simplified, but it isn't incorrect.
>for guns to be used in the vacuum of space
One possible fix I could thing of, at least as a stop gap until a more versatile system is ergonomically possible, is to have the guns stored at a very cold temperature/store in a non-insulated compartment of the ship. Heat will take longer to build to gun destroying levels if you start with a gun at a lower temperature, and this doesn't require any fancy tech other than storing the spacegats uninsulated from the cold of space (so they can, ever so slowly radiate heat off and reach a low temperature). These guns will be just as able to fail at high temps as any gun, just should take longer to reach that point if the start temp is -200 optimal instead of optimal.
>We put insulation in spaceships for a reason. Heat will dissipate, just very slowly.
We put insulation in spaceships to slow heat transfer. Anything exposed to solar radiation absorbs heat. At the ISS that translates to about 260 degrees C. Anything shaded from the sun loses heat, down to around -100 degrees C. Again, this is ISS local weather only. I suspect the shady side temps don't go lower because of conduction from the sunny side.
Anyhow, space ship insulation is there so people don't get fried and then frozen as they bumble around in microgravity.
Once you get into deep space, that's where heat loss becomes a problem.
Going to need some way to vent all that heat, and you might as well implement fluid to conduct heat and be ejected after reaching a certain point. It'll add a lot of mass to any weapon, but at the same time it will hopefully provide enough thermal transfer to prevent your weapon from being turned to slag.
Maybe that's why this thing looks at dumb as it does. It uses a water cooled method to vent heat, so maybe it was actually designed for astronauts.
Also, what about making a weapon that vents all of its heat into the slug fired? Would it be possible to accomplish for a railgun?
Why not return to spring powered or pneumatic or something guns for space?
Like a pneumatic nailgun, except without any (or much) atmosphere your nails fly much further, the mechanism is fairly simple (less points of failure), and really; in space if you can get some little things moving quickly, they're plenty dangerous. So like "space suit to space suit" combat? Regardless of the propulsion method; you would want MORE small fast projectiles so cutting down on storage space for chemical propellants or shell casings is an effective force multiplier.
So basically some kind of souped up space nailgun,
Yeah yeah, you'll still need a way to store the propellant; maybe hose it to a tank attached to the suit, but the thing is you would be able to swap out the magazines to your "fixed" (to the suit anyways, and just by a gas hose) weapon, and carry quite a lot of rounds (assuming they're nail sized flechettes)
>Space has no temperature
American education I take it?
You're both fairly dense. Vacuum can't have a temperature, and it's an incredible insulator. Heat exchange over vacuum is so difficult that, yes, you would have a significant problem with overheating in any kind of prolonged situation.
Also, to answer the main question of the thread, at least part of the initial pressure in any blowback operated firearm is provided by the atmosphere. Depending on how much gas your cartridge produces and how strong your return spring is, some automatics might not completely cycle.
Also, because of thermal and angular dynamics issues, the use of rifled weapons in microgravity and vacuum would be somewhat difficult. In this case, the pump action smoothbore shotgun seems like the most reliable weapon for any kind of vacuum borne firefight.
Why are we gunfighting in vacuum though? Space combat is fucking awful enough without trying to make it an infantry battleground.
>I dunno anything about X but I'm gonna spew my fucking stupid mouth off as if I do!
>Hey, uh, I happen to have a working brain and access to Google, and here's how X really is like: X
>YEAH BUT (made up bullshit) I'M RIGHT FAGGOT
I don't understand how people can be so goddamn dense with an entire internet at your fingertips.
You can learn virtually anything there is to know by typing google.com and then asking the box questions.
You literally don't even have to figure out how to word it just fucking ask your question directly to google.
Oh yeah, hold on, I forgot.
The internet is jam packed full of these same fucking brain-dead slugs that spew opinions and bullshit as if they're fact, and google invariably leads to 7-8 different answers for everything, even if there's only one answer.
>google.com What is 2+2
>Well, see, here's the thing about 2+2...
>DMCA notice 2+2=4 has been removed based on copyright claims by Jesus
There are no fucking particles in space to have a temperature, even 0K which is an absolute lack of temperature. There is nothing to move and bump and vibrate.
If you have a table with nothing on top of it, and someone points to the table and says "How full is that glass of water" do you really say "It's empty"?
BRB shooting myself in the soul.
Totally relevant to anything ever oh wait I'm not a goddamn solar panel k.
>OMG HE SAID EMPTY INSTEAD OF SPECIFYING WHAT IS AND ISNT THERE
Bee Tee Dubs, homie, you already have the brain cancer. And like 7 types of autism.
Bee Tee Dubs Too: Electric Boogaloo: Space IS empty (effectively) of anything that can conduct temperature, which is the fucking physical vibration of particles.
Fuck off all of you.
There is little to no convective cooling in space, but radiative cooling still works plenty fine. Overall it's not quite as fast as in atmosphere, but it would be enough.
you know those vacuum insulated coffee cups?
the ones that keep coffee hot for like 12 hours instead of 30 minutes?
thats the difference between convective and strictly radiation in vacuum
slavic ork boyz already did
Even worse, think about how far each round has to travel. It looks like it loads from where his front hand is, and the cartridge, would travel back to where his shoulder is (at least, if they actually wanted to use that space), and be fired from that point. Then, if looking at the shooter from above, on the way to grab a new round the spent cartridge would be ejected to the somewhere between 0 radians and (π/2) radians.
Isn't space just as cold. There isn't a significant amount of material to conduct heat around the operator or firearm and thus there should be a substandard expansion of gas. Granted this is making me wonder where would the heat dissipate too as there is nothing to transfer energy to.
So on the one hand, if guns don't work in the arctic because they are cold, well space is colder. On the other hand where would the heat energy be released to because in the arctic you have the air to be used as medium for your heat transfer which space would lack in any substantial number.
Well technically anon here is right, temperature is simply a measurement of the kinetic energy of a substance. With that in mind you can't really measure the temperature of nothing.
ARs don't have trouble because the gas doesn't expand enough- any effect the environment has on the expansion of the propellant gases is negligible. It's because their lubricants thicken.
In space, more expensive lubes like graphite could be used. Or they could just use a gun that could run dry, like an AK pattern.
>Because ARs don't like the cold
Bullshit. Just use LSA instead of CLP and you're good to go.
The bigger problem in space is what's called cold welding. In a vacuum two objects of the same metal start fusing together. It's why NASA tools have plastic coatings and tips.
But then you have the issue of the heat differences cracking your brass casings (I'm not talking about reloading, I'm talking about the chamber tempcausing the autoloaded brass to crack, though reloading in space would currently be impossible) and your other heat-sensitive parts (steel etc...)
You could solve the brass issue with caseless ao but you'd quickly get cook-offs.
liquid nitrogen cooled DShKs..
The only way to be sure.
The Sino-American war on the moon surface will be fought with high-tech repeating crossbows and melee weapons by exoskeleton-clad space marines.
imagine a gyrojet rifle, only instead of rockets it fires what amounts to CO2 cartridges with a bangstick on it
Could you guys imagine how awesome bullets work in space? The vacuum would make the gasses expand completely unhindered, increasing velocity. They would maintain this speed indefinitely due to zero air resistance, and thanks to no wind or gravity, there would be no curve in the path.
The real question is what sights would have to be made for space combat.
Jesus Christ you're either a troll or have no idea how physics works.
There has to be SOMETHING THERE for the heat to dissipate into. A material.
Space isn't anything, it's just emptiness. Space doesn't HAVE a temperature in the same way that a box that doesn't exist can't have marbles in it. It's literally exactly like dividing by zero. You can't put energy into nothing.
To radiate heat into space, you'd have to radiate MATTER with it to carry it.
Is you serious son
But the absolute lack of anything to conduct that thermal energy away from the weapon system and allow for some entropy to take place would pose a problem bud
Glawk combined with space telescope.
>Be anti-ship turret gunner on moonbase
>Shooting at enemy ayy ship
>One round misses
>Be peaceful critter on some random planet
>Look up to the dusk sky and see shooting star
>Stare in awe at this majestic omen
>It's getting closer
>Oh fuck it's coming right for me
>Get obliterated by 120mm cannon round
>Stationed on US space platform
>Fuck year 'merica
>Notice space elevator being built
>Coming from mainland China
>Fuck off we though of that shit first!
>Take potshots at chink space engineers all day and lol with the boys at mission control
>May have started WWIII
>Don't care, in space
Actually none of what you said is true. Gravity from one infinitely small piece of matter on one edge of the universe affects the whole universe... Very slightly. And space isn't QUITE a vacuum. But its close.
Shotguns are best for spess warfare
>more enclosed powder than rifles
>shot spreads out and makes multiple holes in an enemy's suit
>shot that misses just spreads infinitely into space forever and ever
>until it lands in paradise
>Omicron Pegasi 47, the clay pigeon planet
Damn, I look forward to Three Body Problem, the movie.
Near future space warfare? Fuck yes.
Selfloaders should work just fine. *That is assuming the ammo was manufactured in a vacuum. Cartridges loaded under standard atmospheric pressure will pop once subjected to pressure difference of vacuum.
>The closest you'd get to being correct are black holes and even then you are wrong
Imagine a white hot piece of steel floating in space. It is radiating light. It is not radiating mass (barring obscure relativistic arguments vis-a-vis the energy of the emitted light having mass).
If you are correct it would continuously radiate light, in violation of the principle of conservation of energy.
If I am correct (I am), then the steel would emit light at increasing wavelengths as it's temperature asymptotically approached ambient.
Which seems more plausible? If vacuum-sealed white-hot steel is a viable infinite energy source, why aren't we using it?
It's a solid sci-fi novel which has won the nebula award, the first of its kind for a chinese author.
>fire a cross bow in space
>the arrow flies off
>159 billion years later it kills an alien
Then they make a tv show about it and other oddities
But Anon the sun is impossible
Once it comes into contact with the absolute zero of space it would immediately cool down and go out
No, you idiot. The part of Earth's atmosphere where the sun orbits has really fucking air.
The same reason the base of a candle's flame is blue is the same reason the sky in the day is blue- they're both at like 500 degrees Fahrenheit
I'm not claiming to be an expert on the subject, just stating my opinion. Unrelated issues such as recoil force on the shooter in zero gravity notwithstanding, I think the biggest concerns would be heat dissipation and cold welding which were both addressed already in this thread.
Definitely. Either that, or load them at 2x standard pressure and see what happens. Some unsealed rounds like 22lr may be alright if depressurized gradually.
>The arrow wouldn't have sufficient escape velocity.
Depends on the orbit you send the arrow on. It could slingshot around the Earth picking up speed from the gravity well and skip off the upper atmosphere.
The amount of downs you are exhibiting has breached autism.
Once you use that source for energy to power something, you are taking energy, and thus heat, away from that system, thereby lowering it's temperature and shortening the amount of time it can be used as an energy source.
Also why is everyone going about this the chemical method?
Why not coilgun? Seriously, magazine fed, coil gun.
Or a rail gun
Or fuck why not laser?
Spaceships can use the gravity of a planet, and the right trajectory, to gain velocity.
It's one of the ideas they have in mind for sending people to mars. And it's also been done in the past regarding unmanned probes and such.
Aside from the possibility of it still leaving earth orbit due to possible conditions and trajectories, I can only imagine some asshat shooting a crossbow bolt and having it come impale him and a space station causing it to depressurize two hours later because he sent it on a slingshot trajectory around earth and it gained 23,000m/s of velocity.
It really depends on your orbit.
The principle behind is that so long as your velocity is pointed in a direction that takes you closer to the Earth, you are accelerating due to gravity without the counter-acceleration offered by the shape of your orbit. Depending on your initial conditions: initial velocity, elevation, shape of orbit, etc., shooting a ballistic projectile could cause it to accelerate enough that it will obtain escape velocity.
The gravity is negligible as long as you aren't less than a few thousand miles from a planet, and the pressure is so extremely low it is basically a vacuum.
Either way, my point is mostly true.
>Yes mass equal to their energy. Hence how gravity is able to effect light
Okay, so heated objects release light which has mass (allegedly). Is there a non-absolute zero temperature at which objects stop emitting light?
It's not alleged, go look it up. And regardless, no material you can make a gun out of emits light in enough quantities naturally to be an effective cooling method for a weapon, which is what this argument's about
Firing 30 rounds semi auto in space any more than firing 30 rounds full auto on Earth would. It's not that big a deal, heat sinks would probably only show up on SAWs and heavier MGs
>It's not alleged, go look it up. And regardless, no material you can make a gun out of emits light in enough quantities naturally to be an effective cooling method for a weapon, which is what this argument's about
This argument is about correcting your ignorance. 1min BRB doing math.
Also, answer my fucking question! Is there a temperature at which objects stop emitting light (other than absolute zero, which is not reachable).
Absolute zero is not proven to be unobtainable cuck, also to answer your other question it's not light it's radiation, if it's light you're after then it depends on what that objects radiative temperatures are for visible spectrum light.
Otherwise it emits specific radiation depending also on temperature for the material and at some point almost all known materials will stop emitting radiation save for a few highly radioactive ones
I'm the one arguing against free energy and for the concept of radiative cooling. You espoused the notion that objects cannot radiatively cool.
You then claimed that black body radiation wasn't a real thing.
You then claimed that, basically, since photon's carry energy they have mass.
This is a debatable matter of interpretation. Regardless, it runs into the issue that I said " (barring obscure relativistic arguments vis-a-vis the energy of the emitted light having mass)" in my previous post.
TL;DR - You're changing your argument because your argument is absurd.
>firing a weapon means all the energy generated goes into the projectile
>which is why bullets are 3x hotter than the sun in flight and why no gun cooling systems have ever been needed to be devised
>The same reason the base of a candle's flame is blue is the same reason the sky in the day is blue- they're both at like 500 degrees Fahrenheit
No, come on? You are fucking trolling right? Please /k/ tell me he is trolling.
That's conduction, or if you're referring to something slightly different, convection.
Heat is radiated in space. That same principle means any raw, unadulterated solar radiation is going to slam into that very black and very absorbent gun and raise it's temperature well past the point where the ammo cooks off.
This is fucking basic shit, I learned this in the 4th grade. Unless you guys are from like fucking Madagascar or some shit you should know this too: http://physics.info/radiation/
>implying a 1atm pressure difference on the outside of the gun will matter given the pressures that operate the gun.
Besides, the gas has already been tapped from the barrel by the time the bullet leaves the muzzle.
>Exactly, and the part of the atmosphere the sun is in is hot as fuck
VACUUM has no temperature, retard
And space is primarily vacuum
The cooling generated by the occasional low energy hydrogen atom colliding with the weapon is effectively zero in comparison to, for example, air cooling.
I didn't say black body radiation "wasn't a thing", I said using it to claim deep vacuum would be acceptable to cool a real world weapon that is generating heat was a stupid thing to do.
So since you seem to be operating on 'somewhat bright sixth grader that read a book on physics that was too complex for him but picked up a handful of terms to use as buzzwords' level. LET ME PUT IT IN SHORT WORDS SO YOU CAN GET IT.
" What stuff is the heat from the gun going into? Heat can't go away into the vacuum. There is no such thing as a 'heat particle'. So where is the energy going? "
There would still be massive heat converted from the kinetic energy of the railgun slug due to friction between the projectile and the rails themselves, which also gains a lot of heat from electron movement during the shot
And without a medium, railguns will still generate a fuckton of heat due to the power used to propel a ferromagnetic slug at great velocity, unless it's sufficiently small enough to kill a man sized target a la F = ma. Even so, we might as well go the thermal clip method of disposable heat sinks when we go into space warfare since passive cooling is unfeasible.
Ship mounted electromagnetic weapons or directed energy weapons can rely on coolant vents instead, pumping them with liquid nitrogen and expelling the high pressured hot gas to cool the weapon. As spacecraft would have larger volumes, coolant tanks are more feasible for larger weapons compared to small arms
first, op says ar OR AK
ak's have gas pistons (or rods if you will)
and a DI ar-15 still functions the exact same way as a piston firearm, because the BCG acts as the piston directly, instead of relying on a cumbersome ak style piston rod
and as already been say, yes, a ar/ak will function fine in space, so long as their are no tuning issues.
Brass can't absorb all the heat because thermodynamics states that heat would travel to cooler areas, say, the other metal parts of a gun like the barrel. Thus your barrel will get hot inevitably and warp itself/other parts of the gun with excessive use, being unable to cool off fast enough via radiation
Spessguns will need to use either detachable barrels or a heat sink with extremely high melting point in order to sustain heavy fire in a vacuum environment without fucking itself
it's russian thinking, when they run out of bullets, they now have a steam powered grenade.
sadly, many /k/osmonauts will incorrectly use the grenade while thinking they are using the firearm.
I did some ghetto math with http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/stefan.html#c2 and http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/cootime.html#c1 and what I've found is that an 18" AR barrel would cool at a rate of about 500 watts at "red hot" temperature, 500 degrees Celsius. Using the other calculator, a steel ball with the same volume of said barrel (blank, couldn't be assed to subtract the space of the bore) would take about 3 hours to cool to around 0 degrees Celsius from 500 degrees. While that's certainly much slower than with air cooling, it's by no means not cooling.
The reasoning for this is that while there is no air to conduct heat away from the object in space, the air would also act as an insulator for radiation of heat off the gun, so while we lose out on one form of cooling, we gain a shittier one.
You're not fully taking into account what I said here: >>28600052
Our atmosphere's protecting us from a lot of shit, one of those things is the blisteringly hot solar radiation that does all sorts of not-nice things. While space is in general real fucking cold, objects in it aren't necessarily cold either.
Oh and this isn't even addressing the problems with metal being metal in a vacuum. This hypothetical AR in space may have enough gas pressure to cycle, but it will eat itself up every time that bolt moves in the receiver.
For those of you who don't know: metal behaves differently in a vacuum. Nothing is there to "tell" the atoms in one piece of steel to not bond with another piece of steel. Normally there's a thin, atom-thick cushion of air or grease or just bullshit, but in a vacuum it's "oh hey we're all the same! let's start sharing electrons boys!" This makes metal in joints slough off and gum up the whole thing. So there will be all sorts of problems with the lugs shearing off bits and pieces as they lock, brass cases sticking to each other in the magazine, just any bare metal touching bare metal is going to have a problem if they're willing to bond at the atomic level.
Yeah cold-welding is an interesting phenomena, but it's easily remedied.
Use of dissimilar materials will prevent it, like for example a titanium bolt locking with steel barrel. Coatings and other surface treatments will also prevent it, but not on parts that have to withstand a lot of shock.
Yeah, and even then there's still going to be a lot of heat in this weapon that's going to keep building and building.
Though that would be a fine reason to paint it white and make it a proper spess boomstick.
>LET ME PUT IT IN SHORT WORDS SO YOU CAN GET IT.
>" What stuff is the heat from the gun going into? Heat can't go away into the vacuum. There is no such thing as a 'heat particle'. So where is the energy going? "
You insufferable cockmongling fucktard... heat is energy. Photons can carry energy. Hot objects emit light, ergo emitting energy. light can travel through a vacuum. Ergo energy can travel through a vacuum. Ergo an object can cool in a vacuum by radiating light.
Go back to school you tard.
Actually in lower Earth orbit there are atoms in the near vacuum of space. When you get to the distance of the Moon, there are about 3-4 particles per cm^3 emitted by the solar wind that's all around us.
Only in deep space you might find less particles since there is a wind from the solar bowshock of nearby stars and the nebulae nearby within a few 100 light years.
So the only true vacuum of space would be in like a dead space distance between galaxies.
Even then there might be relativistic particles that finally slowed down after millions of years emitted from nearby galaxies from supernovae.
So space isn't really empty anywhere except for unreachable realms requiring Star Trek tech.
Even if you got there with such a craft, the heat from your imppulse engines would be spewing hot fusion particles and screw up your readings. The hull material would evaporate ever so slowly and leave a few atoms here and there.
well the gun would work fine the first shot, given it was made of the right materials. you'd have a problem with metals fusing or "cold welding", and lubes boiling off, and heat dissipation....but yeah bullets work in space.