Ultra High Muzzle Velocities

Svtruth;

I seem to recall that sometime in the last few years "American Rifleman" published an article on hyper-velocity "guns". The reason was to simulate micro-meteor strikes on spacecraft as I (may or may not) remember. These were not conventional firearms by any stretch of the imagination, but did produce projectile velocities upwards of 25,000 fps.

Shouldn't be too hard to find the original piece I'd think

900F

If these are the electric rail guns that I'm thinking of they're the size of a house and will only fit on a ship or a few rail cars.

I have no idea what recoil is like.

Click to expand...

Depending on barrel length and the propellant, it may be pretty low for the size and mass of the gun and projectile, and not at all what you'd expect.

Recoil is a function of bullet mass and the rate of acceleration of that mass. Force forward is force backward. Whatever the level of force is imposed on the bullet is imposed on the breechbolt. Equal/opposite.

Look at it this way:

Hypothetically...Two handguns of equal caliber, equal weight, and firing bullets of equal mass.

One has a barrel length of 12 inches, and the other has a stubby 2-inch tube.

If you adjust the powder burn rate so that both guns produce the same muzzle velocity, the recoil produced in the shorter gun will be much sharper than in the longer one...because the rate of acceleration...forward and backward...is necessarily much higher in the shorter barrel. So, the recoil produced by the super gun in question may be more like a gradual, gentle, continuous push than the sudden, sharp "kick" that we understand as recoil.

Another analogy:

Accelerating a car to 60 mph in 3 seconds compared to accelerating the same car to 60 in 30 seconds. The 3-second trip is going to be breathtaking, while in the other one, the sense of acceleration will barely be noticed.

Hmmm...

10's of kilometers/sec. Don't think so - at least not with any conventional material projectile and probably not with any exotics either.

Here's why.

Assume just 10 km/sec. At 3.25 feet per/meter that is 32,500 feet/sec.

60 secs/min and 60 mins/hour = 3600 secs/hour.

32,500*3600=117,000,000 feet. That's 22,159 miles/hour.

At that speed in atmosphere any projectile would melt and melt pretty quickly due to fiction.

For a projectile to survive that velocity it would need to be fired in a vacuum. As one poster has noted guns have been made to do that and the shows that show them can be seen occasionaly on one of the various discovery channels. The guns are used to simulate the impact effects of meteorites on the earth - again as another poster has pointed out.

Short of a miracle we as human beings will never be able to fire any hand held firearm that can shoot a projectile moving at the suggested velocities.

The USN is already planning to use "rail guns" to catapult aircraft from the latest generation of President Class carriers.......And probably will refit them to earlier class members, too...... >MW

WW,

I suppose you could get some impressive velocities - for a short range - from a shoulder-fired weapon provided the projectile was about the size/weight of a sewing needle....Despite our pride in manifold technical accomplishments, Newton still rules our universe........ >MW

^^ I read about the catapults too. Very few moving parts, much easier to adjust for different size planes, and they would run off of the abundant electricity the ship has from nuclear power.

escape velocity vs. rifle velocity

Quoted from Wikipedia:

"On the surface of the Earth, the escape velocity is about 11.2 kilometers per second (~6.96 mi/s), which is approximately 34 times the speed of sound (Mach 34) and at least 10 times the speed of a rifle bullet."

Re: projectile melting and space shots.
Of course, spacecraft don't start off the launch pad at Mach 34...or they too would melt in the lower atmosphere. Always fascinating when a big Saturn V inched its way off the pad, then continuously accelerated to escape velocity. I've forgotten what Mission Control called that number, but it was the point where the ship was committed. 20 July 1969 - what a night that was!

The shells fired from smoothbore (no rifling) tank guns attain some 6000 fps of muzzle velocity. That is nowhere near that of the "rail guns," but nevertheless the higher velocity (than can be attained from rifled guns) is a factor in their effectiveness.