Guy, I initially thought the same thing about the ring, but it's bigger than the bullet, though seats perfectly on the case.
4n2t0, yes, I do the plunk test for the OAL. I had these at 1.065, though I saw other recommendations for longer (1.1" or so) but I figured I should prioritize what passes the plunk test in my individual gun (correct me if I'm wrong).
m700, thanks for the encouragement. It certainly can shake confidence, but you're right, it's overcome-able.
M1A4, I think that procedure is going to be a must for me going forward.
Eirc, no idea, actually. It's a good theory, but unfortunately I have no way to prove it.