The speed of sound is dependent on the temperature and molecular weight of the gas, but not on the pressure directly. the pressure is so high in the barrel that the speed of sound might be 2 or 3 times, maybe even more, than the speed of sound in sea level air.Īlmost right. That 'speed of sound in the barrel' is interesting to think about. Another reason chem propellants suck is the projectile can never, ever travel faster than the speed of sound of the column of compressed high pressure gas in the barrel, but at least in theory theres no reason an infinitely complicated coil gun couldn't launch stuff at any ridiculous speed.
