Recently I was forced to make a switch from Winchester Small Rifle primers to Remington primers due to the great primer shortage that happened a little while ago. Now I have a bunch of Remington 7 1/2 "bench rest" small rifle primers sitting on my reloading bench that I haven't used because that was all I could get my hands on at the time.
The problem I'm having is that about 10% of the loads, the primers pop out of the primer pocket. Normally, I would take this as a sign of pressure and back off on the powder throw. However, doing research on the internet I'm getting conflicting advice. Remington seems to think that 7 1/2 primers are designed for .223 high pressure loads, and many of the loads in my Lyman handbook are done with Remington 7 1/2 primers.
So basically what it comes down to is that I'm loading 62 grain surplus bullets, Remington 7 1/2 primers, in once fired cases, with max loads of AA2230 or Varget (I've tried both) out of a rob arms XCR, and I'm having primers pop out of the primer pocket. All the while, everything I'm reading in my handbook and on the internet is telling me that this is the right recipe for .223 w/ Remington 7 1/2 primers!
Also, when I worked up the load, I went from no signs of pressure to primers popping out of the pocket with no in-between, at fairly low pressures.
As I've said, I've asked around about this, and I'm just trying to put as much data on the problem together as possible. Do any of you guys have any experience with 7 1/2 primers and .223?