May be I should have written further in my post. I don't have a M12 trap gun. This was a theoretical situation that closely simulates the other thread on Roster's article. Let's say it's a modern single barrel that doesn't have an ejection port issue.
Question, if the M12 or the modern single barrel can safely handle the pressure of 2 3/4" magnums why wouldn't you shoot 3" factory shells in it? I agree, that would be unsafe and stupid, but isn't this the same situation as shooting lower pressure 2 3/4" shells in a double gun chambered in 2 1/2"? If you people are right in your thinking - contrary to the warnings of the ammo makers - there would be a very negligible rise in pressure with the 3" shells.
You can't have it both ways people. Why are you faltering on the 3" in 2 3/4" chamber situation?
