Thread: Lapua 6.5 PRC Brass - Split Necks

Originally Posted by 6.5 CRD

Fired brass with the splits in it measures .297 which is SAAMI reamer spec for 6.5 PRC. Freshly sized brass measures .291 and loaded with a projectile .293. So 6 thou of expansion total after springback (not incl however much the chamber grows when firing) 4 thou of that when the cartridge is fired. So theoretically this should be fine? I dont have the gear to measure chamber neck but one would assume it has to be .297 or close to if the brass is coming out at .297? Or should i expect to see less than .297 with the brass if the chamber was .297?

Disclaimer - im far from a gunsmith or engineer just a guy fumbling around with some verniers

You generally get 0.5 thousandths of spring back when firing. So your chamber will be 0.2975 - 0.298 at the most.