The late gun-maker, Carl Hanneken of Southport, NC made over 300 long guns in his career. He worked for Curly Gostompski in Dayton, before setting out on his own.
He made a few rifles with rifled brass barrels. I don't know if this applies to artillery, but he stated that brass is a "dead metal", in that vibrations are minimized when the powder is ignited and pushing the ball out the barrel.
Others may comment on this theory, but even the noted gun-maker, John Braxton, of Snow Camp, NC who made full-size artillery pieces for the National Park Service, said the same thing.
One year at the NC state Shoot back in the '70's, he showed up with a swamped, bronze-barreled, flintlock rifle, .50 caliber that he made from scratch, not parts from TOTW. Hand-made, lock, stock, and hand-rifled barrel.
That weekend, he embarrassed the heck out of the rest of us, shooting' that bronze barrel rifle. Bronze, he said, like brass, is a "dead metal". Minimal vibrations or not "havin' the barrel walk" upon ignition was the success of that gun.
But who among us wants a longrifle with a bronze or brass barrel? That's why you see so few.