In your experience, which of the WSR, BR4, or CCI400 primers is likely the closest duplicate to the Rem7 1/2 primer? I did initial range tests of a new 221 Fireball rifle using Rem 7 1/2 primers with Lapua cases. The results were very accurate and promising using R7 powder or IMR4198 & Nosler 40BT bullets. However, I've experienced issues with the Rem primers protruding too far out of the pocket & not allowing the bolt to close. But WSR, BR4 & CCI400 all seated properly. I tried manually turning a pocket uniformer by hand which didn't eliminate the prob. I just as soon find another primer early on in the range test stage instead of having to start jacking around now power drilling the uniformer in an attempt to get the Rem primers to seat. It's easier just to use one of the other 3 primers which seat properly from the get go.