If you have a gunsmith mess with them, decide in advance whether or not you want the chambers cut to 2 3/4" if they are now 2 9/16". The barrels you have may be 2 3/4" chambered already, I dunno. If they are short chambers, some people want to keep the short chambers. Most gunsmiths will simply stick a full chamber reamer in there and cut not only the rim deeper, but the chamber longer as well. Make up your mind ahead of doing this so you're fully educated on what you want him to do.