Yo, Riley,
Go for it!
I neck down 375/300/7mm RUM brass, leaving that little ring, and fire form to 270 AM all the time.
I have an over flowing bucket of worn out cases, about 16 pounds, and have had no problems.
I switch between COW & corn meal. After forming a few w/COW I need a glass of milk and after a few with corn meal I get really hungry.
Brake seems to make no difference.
Position your dog @ about 15' and shoot at it. The butt wipe magically appearing @ about 10' will scare the heck out of it. I don't have a dog so I fire form at my goats.
Charred material will build up around the case mouth. It there is only a partial ring, that means part Olof it broke off somewhere. Probably during extraction. Put mom's vacuum cleaner on blow and clear the chamber.
Also go slow being cautious of barrel heat.