I've a bud who shoots a Damascus 10 SxS chamber sleeved to 12ga. He shoots sporty clays w/it using modern target loads. He had another prior to the current one. Has shot thousands of targets with them, zero issue.
When you stop to think about it, the .750 nominal bore dia. is the same as the older 12ga. Baker Big Bore bbls. that many people [mostly trap and flyer shooters] were fans of.
FWIW, I had a back bored 12ga. [to .745"] O/U some years ago w/very long forcing cones and could never get it to 'sound' right w/fiber wads. Had to use plastic wads & not all of those tried obturated/sealed all that well. Settled on a couple of plastic wads that never sounded 'punky'. That's speaking to reloads. I never had an issue w/any of the normal factory Winchester AA target loads sounding f'unny'. AA wads have comparatively deep skirts.
