Is it damaging to the shotgun to shoot 2 3/4 in shells in a 3 in chamber? Are the patterns adversely affected?
I’ll touch on it again while there is still a little coffee left in the cup. Those of you who have copies of my old response can compare the two and see where I’ve 1) screwed up, 2) changed my mind or 3) forgotten stuff.
As to question 1, is shooting a 2-3/4″ shell in a 3″ chamber damaging? Nope. Not at all. If it is Beretta is sure in trouble as just about all their target guns, meant for 2-3/4″ shells, have 3″chambers. Of course, going the other way and shooting 3″ shells in 2-3/4″chambers is baaaad. Don’t do that. But you knew that.
But the second question is the big one. Are patterns adversely affected? Maybe yes. Maybe no. As I said above, Beretta uses 3″ chambers in just about all their target guns. Berettas win a lot of stuff. No one has ever accused Berettas of having basically inferior patterns. Then again, Beretta’s high end SO series run 2-3/4″ chambers in target guns. How about that for indecision.
Krieghoff also has tended to use 3″ chambers and also long forcing cones in their respected K80 series, though they use short chambers/short cones in their high end Ulm O/Us. Just like Beretta, they can’t decide, but the high end stuff gets the short chambers.
Perazzi has pretty much stuck to 2-3/4″ chambers for their target guns.
Browning Japan and Browning Belgium generally stick to 2-3/4″ chambers for their target guns. They actually give a reason for doing this. An old Browning FAQ spreadsheet showed pattern degradation when shooting a 2-3/4″ shell in a 3″ chamber. At least that is the official Browning take on it.
One of these days I’ll suppose I’ll actually have to test it and come up with my own conclusions. Until then, I’ll take the manufacturers’ word for it. But which one?
The Technoid writing for Shotgun Report, LLC
(Often in error. Never in doubt.)