Beiruty wrote:How critical is cleaning primer pocket after the sonic bath for 45 ACP or 223?
Not at all. Actually, useless. There have been literally hundreds of millions of .45 and .223 rounds handloaded without cleaning primer pockets and they have fired reliably for decades. Heck, ultrasonic cleaners weren't even in widespread use until the last few years.
I agree the .45 sounds like the classic high primer strike. That is why I mentioned in your other thread where you had pictures of these first 50 rounds that I thought the primers looked too high. Review what I said there about running your fingertip over the case end and feeling the indentation where the primer is seated.
What happens on a high primer strike is the primer is not seated fully into the pocket. The first primer strike simply pushes the primer all the way in without firing the primer. If you shoot the round a second time, since the primer is now fully seated, the second firing pin strike can now ignite the primer. See, a firing pin indentation is not what makes the primer ignite anyway. Seating the primer fully also cause the internal anvil to "pre-crush" part of the priming compound making it ready to ignite, and then the firing pin strike pushes the priming compound
against the anvil that is anchored on the bottom of the primer pocket. The firing pin alone doesn't suffice, it must work against the fully seated anvil.
You should make sure the primer is seated correctly by inspecting every round you make.
Your .223 failure, where the bullet pushed into the case and spilled all the powder appears to be insufficient neck tension. What is your neck OD after sizing and then after seating? Notice I said "neck tension", not "crimping".