What causes trigger bite?

[santacruzdave]

Just back from the range with my new SP-01. Shot almost two boxes of Freedom Munitions 124 gr HPs. Somewhere around the second magazine's worth, the snap of the trigger on reset became really annoying. By the fourth magazine, I was looking for some duct tape to wrap my trigger finger.

I see that there are triggers that address this problem, and I'll get one, however I am really curious as to what is going on and how come it only affects certain shooters/guns?

Anyone have a good explanation?

[M1A4ME]

Trigger size/shape, the trigger guard size and your finger - as well as a bit to do with the loads you shoot.

Most of my CZ's are perfect for me.

However, I have had an issue with one - the P09 in .40 S&W.  I have a P07 (smaller version of the P09) that should recoil more than the P09 due to the P09's weight vs. the smaller P07.  I can shoot my reloads as long as I want in the P07 (DUTY model with the original curved trigger).  But those same loads in the P09 become uncomfortable after a couple magaiznes.  CZ changed the syle of the trigger when they came out with P09's - and then changed it again 3 or 4 years later.

I ended up putting an older DUTY style curved trigger in my .40 S&W P09 and it cured the trigger bite issue.  My 9MM P09 never did bother my finger and still has it's original trigger.

Quite a few people here recommend the older CZ85 style trigger if you have problems with the newer triggers.