Achieve precise bullet seating depth with the Lock-N-Load® O.A.L. Gauge and the Modified Case that fit your firearm's chamber and thread it onto the gauge. This specially prepared modified cases is threaded at the case-head and have a .002" oversized neck to accept the same bullets you intend to load.

This is critical, as the Lock-N-Load® O.A.L. Gauge dimensions obtained will be accurate to .001". These results cannot be attained with competitive products, which use a simulated bullet with an arbitrary shape.