Gel Test: Pistol-Length AR Barrel

BACKGROUND

One reason shooters thinking about home defense, or law-enforcement or private security professionals equipped with SBRs have this question is because of the existing data based on full-metal-jacket military rounds, the 5.56mm 55-grain bullet. That 55-grain bullet is designed to tumble and then break in half, but that only happens at higher speeds when the bullet is inside the body. So there is an effective range of where the bullet is expected to be going fast enough inside the body to tumble and break. For any load, the speed is dictated by the barrel length to a certain extent.

Naturally, shooters worry if they will be able to stop a threat shooting 5.56. Will the bullet tumble or not when fired out of a ten-, eight-, or even six-inch barreled AR as in this video?

MODERN AMMUNITION

Remember that we are using modern bonded hollow-point rounds, rounds that are made for close-quarters defense. Shooting from about 15 feet away, a common home-defense distance, Rob tests one of these rounds in a 16-inch gel block to see if it tumbles and breaks within the block.

GEL TEST RESULTS

Did the bullet expand as we need it to when we’re using self-defense weapons? As the gel block shows, it did. The bullet came in, expanded at about two to three inches within the block, tumbled to the side and then expanded again at about eight to ten inches within the block. If the block were a human body, the damage would happen within the thoracic cavity.

In conclusion, as this gel test demonstrates, even out of a six-inch barrel, a proper modern bonded hollow-point or split-core bullet will do what it’s supposed to in a home-defense scenario or in an armed professional’s patrol rifle.