What might cause a shotgun to explode?

• A. Using the wrong shotshell in your shotgun
• B. Using the wrong powder
• C. Shooting at a person
• D. Using a larger gauge

Answer: (A)

Using ammunition that doesn’t match your shotgun is the main risk for a catastrophic failure. Shotguns are designed to handle a specific gauge and shell dimensions, and the internal pressure from a shell is calibrated for those specifications. When a shell that doesn’t fit—whether wrong gauge, wrong length, or incompatible load—is fired, the combination can create far more pressure than the gun is built to contain. That overpressure can cause the barrel or action to fail, sometimes violently, sending fragments back toward the shooter. Factory shells are tested for a given gun, so always match the shell to the gun’s gauge and chamber length.

Shooting at a person is dangerous and illegal, but it doesn’t describe the mechanical failure pathway. Using the wrong powder is a reloading error you’d encounter in assembling ammunition, not a mismatch you’d typically experience with factory loads. Using a larger gauge isn’t something you should do in a gun designed for a smaller gauge, since shells won’t fit correctly and can lead to dangerous chambering issues, but the direct cause of an explosion from normal use is the mismatch of the shotshell to the firearm.