m&p45acp10+1
New member
Case rims from AR brass tend to bend. Some brands do it worse than others. The worst offender I have encountered to this day has been R-P. When I used the Lee trimmer that goes on a drill. The R-P cases had a bad habit of wobbling out of the shell holder. Abut 8 to 9 out of 10 did this from factory loads. Other do it as well.