Smyth Busters: Will Excess Bullet Setback Blow Up Your Gun?

An old nugget of reloader wisdom warns that too much bullet setback can lead to your gun blowing up. Is that true? Don't worry, Brownells Gun Techs™ Caleb and Steve, aka The Smyth Busters, are on the case. Bullet setback refers to how deep the bullet sits in the cartridge case. As a round is going into the chamber, sometimes the bullet jams against the feed ramp and gets pushed deeper into the case. The bullet in turn compresses the powder charge, leading to a spike in chamber pressure that CAN be strong enough to damage the gun. At the very least, regular exposure to excessive pressures will cause accelerated wear on the gun. Worst-case scenario: your gun blows up, with collateral damage to YOU. The risk is higher with maximum-pressure handloads and commercial +P ammo, and rifle cartridges are not immune to the effects of excess bullet setback. Most guns are built to handle more pressure than the normal maximum pressure of the cartridge, up to twice as much, but it's not a good idea to chance it. The bullet jamming down into the case also causes the case to swell, which can lead to feeding problems - not something you want during a self-defense emergency! Some gun designs are more prone to feed problems caused by a bulged case, the 1911 for example, but Glocks much less so. So it's NOT a myth: Excess bullet setback CAN lead to damage to your gun or even a KA-BOOM.