I have about 4,000 CCI 400’s
And I’m down to my last 2,000 BR-4’s
I tried using the 400’s in my 6.5 Creedmoor low node load that is 2650fps and my 6BR with Hornady 75gr V-Max at 3,200 and both popped primers where where the BR-4’s never did.
I never popped a primer with CCI 400’s in 5.56