Hear is my story, year and a half ago. New 45 BC, and had a couple of factory 454s I bummed. Fit right in. Cool. Being new to all this I asked some advice and studied. The consciences was don't do it. I didn't believe. So a bought a bag of new 454 starline brass. Just for safety I chambered one, the new brass, did not seat, could not close, and when forced the new brass stuck in the chamber. After ramming the brass out and examining it, I found the throat had been forced into the forcing cone. Conclusion, a factory or reloaded, crimped round fit right in but the brass was laying on the forcing cone. A recipe for disaster. Same as having a barrel obstruction. Solution, trimmed the brass 1 or 2 thousandth off the brass and shot 454c loads. Worked fine. I don't do that anymore, the bruises got to be to much. As said before, my 45LC now sits on topper wood and frame and I have fired hundreds of "Ruger" level loads, deadly, no need or desire for them big bangers.