Have you removed the trigger group before? It's quite tricky on the large frames; I recently added a spring kit to my 357 max and had to end up calling CZ and talking to the DW repair guy to see what I was doing wrong. I posted how I did it. Wolf spring kits come up on Ebay and the gun auction sites from time to time, that's where I got mine. It will make your primer strikes lighter. I use Winchester primers and have never had a dud, but I have had a few CCI primers that didn't go on the first strike, but fire when restruck; not good when hunting. Be wary of target spring kits; I put one in a 357 mag and single action was so light that you couldn't touch the trigger until on target.