Today was the first chance to try out the MCarbo striker spring in my PM9. I could not be more pleased. No light strikes with 4 different brands of ammo. MUCH lighter trigger pull. That helped my accuracy a lot. I needed that. Highly recommend it.
Update: Well back to the range today and no joy. Six fail to fire using the same Winchester Nato 9mm ammo I used last time. I will change the spring back to stock and see if that fixes the issue. I hope it was just some bad ammo. Six miss fires out of 100 rounds is no good.