How hard is it to have the chamber lengthened to 2 3/4"?
Might be quite a bit easier, and cheaper, than what you are doing.
Brownells sells reamers to open up those old shotguns to accept 2&3/4 rounds. I have one for 12 gauge. I have done 3-4 of them. There is an engraved line on the chamber length gage and you cut until that line ends up even with end of the chamber. When I bought mine, the gage came along with the reamer. I don't see that now.
I think I paid about $60 for mine.. More expensive now.
https://www.brownells.com/tools-cle...rcing-cone-chamber-reamer/?sku=080661020
