<P> Muzzle velocity is the speed of a projectile at the moment it leaves the muzzle of a gun . Muzzle velocities range from approximately 120 m / s (390 ft / s) to 370 m / s (1,200 ft / s) in black powder muskets, to more than 1,200 m / s (3,900 ft / s) in modern rifles with high - performance cartridges such as the . 220 Swift and . 204 Ruger, all the way to 1,700 m / s (5,600 ft / s) for tank guns firing kinetic energy penetrator ammunition . To simulate orbital debris impacts on spacecraft, NASA launches projectiles through light - gas guns at speeds up to 8,500 m / s (28,000 ft / s). </P> <P> The velocity of a projectile is highest at the muzzle and drops off steadily because of air resistance . Projectiles traveling less than the speed of sound (about 340 m / s or 1115 feet / s in dry air at sea level) are subsonic, while those traveling faster are supersonic and thus can travel a substantial distance and even hit a target before a nearby observer hears the "bang" of the shot . Projectile speed through air depends on a number of factors such as barometric pressure, humidity, air temperature, and wind speed . Some high - velocity small arms have muzzle velocities higher than the escape velocities of some Solar System bodies such as Pluto and Ceres, meaning that a bullet fired from such a gun on the surface of the body would leave its gravitational field; however no arms are known with muzzle velocities that can overcome Earth's gravity (and atmosphere) or those of the other planets or the Moon . </P> <P> While traditional cartridges cannot generally achieve a Moon escape velocity (approximately 2300 m / s) or higher due to modern limitations of action (firearms) and gunpowder, a 1 gram (15.4324 grain) projectile was accelerated to velocities exceeding 9,000 m / s (~ 30,000 ft / s) at Sandia National Laboratories in 1994 . The gun operated in two stages . First, burning gunpowder was used to drive a piston to pressurize hydrogen to 10,000 atm . The pressurized gas was then released to a secondary piston, which traveled forward into a shock - absorbing "pillow", transferring the energy from the piston to the projectile on the other side of the pillow . </P>

What is the muzzle velocity of an ar-15