FWIW, I went through a 500-round box of Federal "Black Pack" and while it shot like doo-doo, it ran fine in my PX4s. I mostly run my handloads with 124s at about 1100 fps and those cases and range pickup Blazer Brass cases have caused no problems in my PX4s and Walther P99Cs. It might be because my loads are hotter than the anemic factory Blazer.