First make sure your FL resizing is being done correctly and fully, the first thought that came to my mind is that it's not getting fully into battery as spqrzilla mentioned. If you are right on the fine line of some going in and some not going into battery, this is also potentially creating a tight to zero headspace in your gun and greatly increasing your pressures. That would be the case if you aren't pushing the shoulder back far enough. Take your FTF rounds and start measuring them very carefully and I'd bet you'll find your problem.

as to the OAL moving around while crimping at the ogive, get a good brass trimmer and trim to the correct length and seating at the Ogive should give you SAMI spec ammo and should eliminate all the issues you are seeing.

It's the ONLY way I would ever load ammo for a semi-auto. If you are putting out ammo that is at SAMI spec all the way around you aren't going to have problems like this.

I also agree that the chances of "bad primers" is slim to none.