Testing some loads for increased velocity and accuracy in a Remington .223 BDL. The first load of 25.8 grains H335 behind a Sierra 60 gr HP. 2- five shot groups measures .587 and 0.857 respectively. No obvious signs of pressure. Next group was 27.1 grains H335 behind previously mentioned bullet. Shots 1 and 2 no problem, shot 3 I felt a sting in my right cheek (Thank God for safety equipment). I never had a pierced primer so I examined everything and no problems were detected. Shot number 4 had no problems. Shot 5 resulted in another pierced primer so I abandoned testing this load. Of note: OAL was 2.250 Sierra lists 27.1 of H335 as max behind 60 gr Sierra HP Primers were NOT flattened Brass was new Lapua Primers were Winchester small rifle Obviously, no crimp The last group measures .0339, to bad it cant be used. Question? Is this an obvious overpressure issue?