I am trying to find out if a #3 will handle large custom rounds, like a 300 ultra mag, I have the utmost faith in the #1, but I can't find much info on the strength of the #3. Also If any of you are still looking to change triggers in a # 1, the moyer is a great do it yourself job, if you are up to a challenge, if not the kepplinger is worth the extra money.