My SP01 Shadows has the CGW 11.5 main spring, their firing pin and spring. I've never had a light strike on any primers. Couple weeks ago at Area 4 i had 3 failure to fire on the first shot, it happened again last week at our club match. I was finally able to recover the round and there was no mark on the primer. It appears the firing pin spring was not returning the firing pin back far enough. I've never heard of anyone having that issue so thought I'd post it to help out. I've added the firing pin spring to the trigger return spring and slide stop in my repair kit.