Muzzle Velocity

As a general rule, long guns lead to higher bullet speeds. This is because with a long gun, the explosion is contained for a longer period of time – the propulsive force has no choice but to expand down the barrel and give the bullet a longer “push.”

With a handgun, the barrel is quite short, so within a few inches of “pushing,” the explosive force comes out the end and dissipates into a muzzle flash.

Also, muzzle velocities are a product of both the firearm and the ammunition, so any numbers are generalizing based on what’s typical.

Some typical velocities of common handguns, in feet-per-second.

• .45 ACP: 850 fps
• 9mm Parabellum: 1,220 fps
• .357 Magnum: 1,450 fps

Some typical velocities of common long guns:

• .22 LR: 1,250 fps
• AK-47: 2,350 fps
• Barrett M85 .50 cal: 2,800 fps
• .30-06 Springfield: 2,900 fps
• M-16: 3,100 fps

Note: 1,000 fps is 681 mph; so the bullets of an M-16 are traveling at 2,113 mph as they leave the end of the barrel.

At at about 1,110 fps, a bullet will break the sound barrier. This leads to a much louder weapon – you’ll hear a signature “crack” in addition to the propellant ignition. To counter this, some weapons can be loaded with “subsonic” ammunition, which is designed to leave the weapon at a lower speed. This ammunition is often heavier in order to retain stopping power despite the sacrifice in velocity.

Why I Looked It Up

I just always wondered. In particular, I wondered why long guns were both more accurate and more lethal, as a general rule. Turns out that in addition to the increased stopping power of a higher velocity bullet, the increased velocity contributes to a flatter trajectory over distance (the AK-47 is notorious for its inaccuracy, which turns out to be partially due to a lower muzzle velocity).