I picked up a new to me Beretta M9 today. First thing I did was take it home to clean it, then I headed to the range with some Xtreme 124 gn plated and some of my own cast 130RN sized to 357. The first 70 rounds were the plated and my groups were all over the place for me. I then switched to my own cast rounds and low and behold my groups tightened exponentially!
I went home and slugged the barrel and found it to be .3568. My cast mic’d at .3566 and the plated mic’d at .3550. I could stand to try a sizing die at .358 perhaps?
The top group is a sample of my cast group, and the bottom two show the variation I got with the plated rounds.
All shots off hand 7 yards. Each group is one mag.