My results may not help you since all I shoot are my own reloads. I have two P-09's, one in .40 the other in 9mm, the .40 cal I run an 11lb hammer spring, in the 9mm I run a 13lb hammer spring. Both guns have the extended CGW FP, both guns are 100% reliable with S&B primers, Win, CCI, and Federal. I do seat my primers very deep and give them a slight crush which I'm sure helps.