What action would you consider the most durable modern O/U action? Let's say we limit it to models produced in just this century and keep the original MSRP below 20K.
Krieghoff, Beretta, Perazzi, Browning, Benelli, Blaser...something else?
K80, Kolar, Perazzi, and Blaser would all be contenders for most durable. Of course, at a horrible cost of weight. They are overbuilt, extra have clay guns and are the antithesis of a lively wingshooting gun.
Both Beretta and Browning have made hybrids that can be used for both purposes, but less durability.
Better yet, a Purdey, Dickson, Woodward, or Boss would be the ultimate in lightweight game guns. Naturally, their useful lifespan is 1/20th the amount of shots before they are rubble.