Folks, I have a question I'm hoping someone on here has a better answer than what I came up with. I had a couple of 45 LC empty but primed brass that I decided to cycle through a revolver to demonstrate something without putting dangerous lead out the other end. Both were from original factory loads with the bullets pulled. One was S&B (Sellier and Bellot) and the other was Winchester USA headstamp brass. When fired, the Winchester experienced profound primer setback, enough to make cycling the revolver difficult, and requiring disassembly to remove. The S&B had no such problem. What I found surprising was that the primer was setback at all, when there was basically no back pressure on either cartridge, say from powder or a bullet.
I have fired a number of both of these factory loads and never experienced a primer setback with an intact cartridge (powder and bullet in place) so why does the empty case experience this? Is there something about the resistance provided by the intact case that actually lowers the pressure? Seems counterintuitive to me.
Thanks for your thoughts!
I have fired a number of both of these factory loads and never experienced a primer setback with an intact cartridge (powder and bullet in place) so why does the empty case experience this? Is there something about the resistance provided by the intact case that actually lowers the pressure? Seems counterintuitive to me.
Thanks for your thoughts!