Thanks for the diagrams Lancaster.

I purchased a trim die along with the reloading dies from CH4D. I've never used one before. Till now, the only major trimming of brass I've done is cutting 223s down for 300BLK. I have only a couple of empty hornet cases lying around. I might sacrifice one towards learning how to use the trim die while I wait for the machined cases I've ordered from RMC.

My understanding is that because the rim needs thinning, even if I can trim the brass correctly, I'm stuck without having a lathe to do the thinning. I am assuming you can do that for a few cases on a drill press.