I've shot a hell of a lot of singles trap with an O/U Beretta.
Just this year, I finally broke the lower hammer. This is a known weak spot with this design, and it was expected - eventually. 50,000 targets or thereabouts.
Admittedly this is a target shotgun, but inspection showed no wear anyplace I could see without major disassembly. The replaceable bolt pins and shoulders are still a long way from needing replacing. There is zero visible wear on the trunions or barrel pivot points.
I'm guessing your average well made double should not mind frequent use, and I agree that most wear is caused by lack of clean lube on the hinge pin.
