Some plated bullets are extremely sensitive to the crimping process. I experienced it with my .40 and I stopped shooting plated altogether because I could never resolve it to my satisfaction. The problem I was having seemed to be the plating was shedding causing weird aerodynamics, leading to unpredictable results downrange.

The best I ever got them to behave was by using a chamber check guide and only putting enough taper crimp on the round so it would enter the chamber check smoothly. Still wasn't a 100% fix, so I went to moly coated bullets.