Lot of dead guys in that old post, Gene.

Low pressure 2 3/4” loads will be fine in 2 1/2” chambers. I used to advise guys with Darne guns to lengthen the chambers if that was what they wanted to do, but, I’ve eased off on that, after seeing the results of some hack gunsmithing. I don’t believe, correctly done, it is a problem for the gun, just that good gunsmiths aren’t running around in bunches.

Best,
Ted