I bought new PMC brass and loaded my favorite load which is a upper end of the medium range in the Sierra manual. Each fired case split. I reduced the loads to starting loads and the cases were still splitting. Every case that I fired had split. I loaded the same medium loads in Hornady, RP, and Winchester brass and none of then split when fired. Is PMC junk or prone to making bad lots of brass at times. The funny thing is the brass ejects like normal, no hard to remove or stuck cases, no flat or blown primers, primers look normal after fired.