9mm target loads, 3.9 gr Bullseye, RP # 1& 1/2, small pistol primers, 125 gr Missouri cast lead bullet mixed brass.. Top rounds fired from my Sig 229, Lower ones fired from my Browning Hi Power. Same day, same load. None of them were louder or stronger or in any way different from normal. Primers are not flattened at edges, but the firing pin dent is flattened out and appears to be scraped by the firing pin hole. Small fragments of brass found inside the firing pin return spring on the BHP. Seen this before? In 40 years of reloading & hundreds of thousand rounds, I've never seen anything like this.