The science of weaponry...need some help here guys!

[Tyyr]

What's that solve?

[Mikey]

Heres a thought. Instead of bullets propelled by an explosion (ie, regular gun), why not magnetic acceleration?

I think MetalHead was looking for something at (or close to) current tech. A rail gun or coil gun small enough - not to mention reliable enough - along with an easily-portable power source for such a weapon pretty much falls into the "death-ray gun" category.

[stitch626]

Heres a thought. Instead of bullets propelled by an explosion (ie, regular gun), why not magnetic acceleration?

I think MetalHead was looking for something at (or close to) current tech. A rail gun or coil gun small enough - not to mention reliable enough - along with an easily-portable power source for such a weapon pretty much falls into the "death-ray gun" category.

Just curious, how much power would it take to generate a magnetic field (in similar form to MAGLEV trains) to propel a metal bullet (lets say 9m) to normal speeds?

Though, now we realize why energy weapons exist in Trek (other than they look cool).

[Mikey]

Just curious, how much power would it take to generate a magnetic field (in similar form to MAGLEV trains) to propel a metal bullet (lets say 9m) to normal speeds?

I'm not sure what you mean by "9m." A 9-meter bullet, or a bullet with a 9 meter range?

Anyway, I'm not sure; but for hand-held purposes, we'd probably be looking at a single-stage coil gun. That would imply a pretty high current. Additionally, since it would be awfully hard to keep the coil of a sidearm or longarm cold enough to superconduct, you're also looking at a very hgh impedance for the coil. All this adds up to "I don't know - but a lot."

[GrahamKennedy]

1 - Would projectile/ballistic weapons as we know them even function in a vaccum?

I'd say yes, and I'd imagine it would not need any real modifications to do it. A round of ammunition doesn't use the "outisde" air for combustion, the oxygen required is part of the makeup of the explosive within the round. So yes, you should be able to fire the gun. In fact since it's not having to push and air down the barrel ahead of it, you'd probably get somewhat higher muzzle velocity out of the gun.

2 - Assuming the answer to the first question is "yes", in a vaccum, would projectile weapons (guns/cannons/etc) prove slightly more effective upon impacting their targets, as there is no air resistance to slow the shots down over large distances?

In most cases, the bullet slowing down isn't really the limiting factor in the range of the weapon. Bullets do indeed slow as they travel, but they are generally still going at a fair old clip when they hit what they're being fired at, be it the target or ground, etc around it. That said, it is true that in space the bullet will just keep on going, essentially forever, until it hits something or until the gravity or some body pulls it in. Theoretically you could fire your rifle from a million km away; your problem becomes one of aiming, since it will take a long time for the bullet to get there and the target's probably moved on by the time it does.

3 - Can things explode in a..uh, shall we say, cinematic sense in space? As in huge balls of fire? Or would it literally be an unseen wave of force?

Depends on the things we're talking about. A man in a space suit hit by bullets will leak his air pretty damn fast - by my very rough estimate one 9 mm hole will empty a suit in a matter of a few seconds, but it's a gush of air, not likely to be any kind of explosion. Similarly a ship hit will empty of air pretty quick, barring internal subdivision to prevent that. If you hit something flammable in a ship then yes it will explode, but the fire will only last as long as the air does.

If a major hit on a ship struck something like a fuel tank full of flammable fuel, bursting the hull open as it did, then I'd guess you would get a big ball of fire that would very rapidly expand and disperse into space, going out as it did. Unburned fuel and stuff would then just leak out of the ship. If the hit left a major breach in the hull that was emptying the air then that initial fireball might turn into something like a pillar of fire rushing out... but it would only last as long as the air did, and then go out very abruptly.

4 - If the answer to the above is "yes", would more damage be caused through the actual heat/flames or simply the overpressure wave?

Outside the ship you'd have very little damage at all. If you had some sort of artillery shell explode near the ship then there would be nothing to carry the blast except the material of the shell itself, which would be pretty small. A pure blast type weapon would be next to useless in space. Some sort of fragmentation warhead would be far better - something with a steel case that exploded into splinters which would hit the ship. Even better if it could be directional somehow.

Inside the ship blast would propogate much like anywhere else, for as long as the atmosphere lasted.

One fun possibility is that bits of the ship could be heated to very high temperatures by a weapon strike. The fire vanishes when the air rushes out... but without air for convection, hot bits of the ship can stay hot for a long time. If you should seal your hull breaches and flood the area with air, it's perfectly possible that fires would suddenly break out all over the place. Even on Earth it's not unknown for a fire to lie "dormant" like this when it's used up the air in a room, then flare up when somebody opens the door - just like the movie Backdraft.

[stitch626]

Just curious, how much power would it take to generate a magnetic field (in similar form to MAGLEV trains) to propel a metal bullet (lets say 9m) to normal speeds?

I'm not sure what you mean by "9m." A 9-meter bullet, or a bullet with a 9 meter range?

Anyway, I'm not sure; but for hand-held purposes, we'd probably be looking at a single-stage coil gun. That would imply a pretty high current. Additionally, since it would be awfully hard to keep the coil of a sidearm or longarm cold enough to superconduct, you're also looking at a very hgh impedance for the coil. All this adds up to "I don't know - but a lot."

Sorry, I missed an m. I meant the standard handgun 9 mil size... (mil does mean millimeters, right?)
Though a 9 meter bullet would be interesting.

[Mikey]

Gotcha. I'd say that's a bad idea, though. If the amount of propellant you can fit into a cartridge (or design the action of a gun to be proof against) isn't an issue, there's no reason to go with a bullet that small.

[stitch626]

Hmm, ok. The amount of knowledge I have about firearms (which includes their individual pros/cons) could fit in a flea's nose.

[Mikey]

Bear in mind that you can probably make a coil gun in your basement with a 120V source and some capacitors from a camera flash. What I'm talking about is the feasibility of making something useful for a soldier in the field, with the reliability, selective fire feature, etc., that that entails. With current tech, arming a man with a personal coil gun of today would be like sending a soldier onto a modern battlefield armed with a musket.

[Mikey]

Hmm, ok. The amount of knowledge I have about firearms (which includes their individual pros/cons) could fit in a flea's nose.

Well, you know this much - a round for a firearm is a cartridge containing the primer, the propellant, and the bullet (there have been guns for caseless ammo, with the primer and propellant made into a "cake" to which the bullet is glued, but they've been less than succesful so far.) The amount of propellant is of course limited by the size of the case, but also dictated by the size of the bullet - a heavier ball needs more propellant to get to a given speed than a smaller ball. However, a heavier/larger bullet will tend to better ignore the effects of windage, etc. - that's why the most succesful sniper rounds today are the .50BMG's (12.7mm.) Of course, Steyr makes a 15.2mm APFSDS, but let's forget about that for the time being. In general, a bigger bullet makes, logically, a bigger wound (there's also what's called hydrostatic shock, which is the ability of a supersonic round to cause collateral damage in a target - an M-16 round can cause cerebral hemmorhage from a hit to the upper chest, for example, but for our coil gun example we can figure that different sizes of bullets will be travelling at roughly similar speeds.)

The coil gun would be loaded with just a bullet. Without the size of a cartridge, the explosive pressure on the action, the amount of propellant, etc., to worry about, there wouldn't be any reason to use a smaller round than a larger one.

[stitch626]

Got it. So the only limiter would be the power source...

[Tyyr]

And you've still got to deal with the recoil effects of the gun and the heat from your power source.

[Laughing Man]

Recoil could be compensated by increasing receiver mass of the weapon, ie heavier being acted upon less, this would require different receivers for different gravity/atmosphere/mobility issues.

Then ammunition doesn't need to be uniform in all situations, With no atmosphere a particle like a scraping of paint or iron filing at extreme velocity would be as lethal as say, 9mm slug on softshell pressure/atmosphere suits and possibly do good damage to it's inhabitant too. The required outcome of combat may not always be decompression.

That said Tyyr and Graham have covered all the bases nicely,

[Laughing Man]

Also, RE 3)

During decompression, does the atmosphere cloud as the pressure changes? it happens in bottles but does anyone know how it works in larger areas?