I have a good shooting buddy that’s using 4.55 grains of w-231 with 124 gr pd jhp at 1.12. He’s using a seven pound spring in a ck, never seen it malfunction. I am using the same gun and load except with 4.3 grs of aa#2 always runs like a top. I’ve tried all kind of different loads and the gun runs flat with these low power loads and still functions fine. Both loads are running around 134 pf.