I was just doing a bit of reloading and thought I'd try using some different .223 cases to see how the POI changes when using the same load, trim length etc.
I primed a load of SAKO brass no probs. Prvvi brass, no problems. Federal brass, the primer wont fit in the pocket without deforming, I even chamfered the hole slightly but that made no difference. It looks like the primer pockets are off centre on some and most are under sized!
Not very clear in the pics but here they are anyway.
Note the ring around the primer pocket on the Federals.