"Houston, we have a problem"

[LR1955]

Hoot you did not say what type of brass it was you were using. In my case I checked everything I could as you did. I think the brass I had was over annealed giving it too soft a shoulder because I did not have any problems like this in the previous 1K rounds I had loaded.

Rasp:

I believe you are right that the brass was improperly annealed. Honestly, it has never happened to me with any cartridge. If the seating die was cut too short, every single piece would get crushed.

Good luck getting any brass manufacturer to admit it though.

LR55