Hornady

: -Curved model-For all autoloader, lever-action, or pump-action rifles-Also fits all bolt-action & single-shot firearms-Inserts into chamber through ejection port-To use the Lock-N-Load® O.A.L Gauge, you will need a Modified Case (sold separately) to fit your firearm's chamber & thread it onto the gauge-Dimensions obtained will be accurate to .001"*Not compatible with Adapter "D" or short-bodied cases