Hornady Lock-N-Load Cartridge Gauge 300 PRC

The Hornady Lock-N-Load Cartridge Gauge for the 300 PRC is a precision SAAMI-spec chamber-check tool that lets reloaders confirm their cases and loaded ammunition will drop freely into a standard rifle chamber. Machined from steel with a silver finish, this caliber-specific gauge is part of Hornady's Lock-N-Load reloading ecosystem and is built to the same SAAMI dimensional standards as production 300 PRC chambers.

The 300 PRC (Precision Rifle Cartridge) is a magnum-length bottleneck cartridge built around a .308-diameter bullet, and its SAAMI dimensions are tighter than many legacy magnums. Dropping each fired and resized case, and every finished round, through the gauge catches over-stretched brass, improperly sized necks, and out-of-spec ammo before it reaches the firing line, helping prevent stuck cases, hard chambering, and pressure irregularities at the range. As an at-the-bench quality control step, it is one of the simplest ways to confirm a reload is safe to chamber.

To use, simply ensure a correct fit by dropping sized cases or loaded rounds into the top of the gauge - if the case falls fully into the chamber, it will chamber in your rifle. The Lock-N-Load Cartridge Gauge is a measuring and QC tool only and is not intended for decapping, resizing, or as a substitute for proper load development with a current reloading manual.