On reloading a carbine the brass is bad about growing in length. If it gets past trim length, it will go over pressure as the gun headspace's on the case mouth. I have a couple and they like clean, trimmed brass, watch cast bullets, with lead shavings at the case mouth.

“To expect defeat is nine-tenths of defeat itself. It becomes a self-fulfilling prophecy. It is best to plan for all eventualities then believe in success, and only cross the failure bridge if you come to it."
Francis Marion - The Swamp Fox