When loading fmj precision delta 124gr 9mm bullets, about 1 in 10 rounds are not holding the bullet. A little pressure and the round falls into the case. On the rounds that are holding, no amount of pressure will get the bullet to move. However, some of the rounds just aren't holding. I've identified the problem as isolated to certain brands of brass, but I'm not convinced that the brass itself is the issue. I've never run into this problem when using zero bullets, but I just bought 2000 PD bullets because zero was out of stock. I don't have any zero bullets left to check against, but the precision delta bullets are measuring .355 at the base, but .353 before the olgive where the round is being lightly crimped. Is this normal?