I have the same 550 in the same caliber and my set trigger has never done that. It seems to work fine. I have no gripes about it and it shoots great. The trigger is pretty crisp without setting it so I hardly ever use the set feature. It kicks enough that I don't like the very light pull. Amazingly, the best accuracy I have found is the Prvi 285 grain factory loads and they work great on game. It will shoot 1" groups all day and my handloads are no better. Plus it's pretty reasonably priced. It's Mauser enough for me and it is one of my favorite rifles.
