Nope, that occurred in many places. Cast bullets in the .40s especially were a terrible combination. ISP had reloaded for decades for their S&W 9mms for practice ammo, but the S&Ws had cut rifling. The Glocks, having polygonal rifling, hate cast bullets. This is not just Glocks but H&Ks and some Kahrs too. Plated and jacketed bullets run great.