Definition:

A gas check is a metal cap or cup applied to the base (bottom, or rear end) of a bullet.

Gas checks are commonly made of copper or aluminum.

The purpose of a gas check is to prevent the melting of the base of cast or swaged bullets when they are fired. The extreme temperatures of burning gun powder can melt bullet bases, especially when the loads are "hot," or towards the maximum powder charge.

This can cause poor accuracy as well as allowing the lead to coat the inside of a gun's barrel, clogging up the rifling.

Gas checks are commonly added to cast bullets during the sizing process.

- Russ Chastain

Glossary Index