Of all the break action shotguns that I've had, the breech face has never been a component of the lock-up. And I have to admit that watching the best Perazzi 'smith in the US fitting a number of barrels for me revealed only his interest in the proper fitting of the flats and the bolt. Ejectors may rub on the standing breech but not the barrels proper.
IIRC you have a Perazzi that is mondo difficult to open. Lucio could fix that badly fitted barrel for you in a couple minutes. You'd be amazed at how easy a Perazzi is to use when it is right.

Just a thot

Dr.WtS
Mysteries of the Cosmos Unlocked
available by subscription