I've got a S&W K-22 target revolver with factory-installed McGivern front sight bead that my great aunt bought new in 1936 for $38. I have the original red box and receipt to prove it. In 1960, when I was 9 years old I became the first person ever to fire it. (If I'd understood anything about collector's value then, I never would have). It still shoots great. Nothing has ever been replaced.
In his book, Fast and Fancy Revolver Shooting, Ed McGivern showed before and after groups from that same model weapon when he sent it in for a factory overhaul at something like 200,000 rounds, IIRC. (Maybe it was just 100,000, but the bigger number sticks in my head for some reason; its been awhile since I read that book.) In any event, it illustrates how well a gun can keep going. The low power and soft lead projectiles in the .22 LR won't punish a gun much, so this may well be the best case.
Based on Sierra tests, .308 barrels are shot out in 3,000 to 3,500 rounds (CR or SS, respectively). That matches my experience the the M1A. Hotter rounds shoot out even faster, with some of the monsters like the .300 Baer having trouble going much over 1000 rounds. They represent the worst case need for maintenance. When you change a barrel you usually don't have to do anything else, though it is usually the time at which bedding gets looked over or refreshed and dimensions and firing pin protrusion and other gauging is repeated just to be sure all's well.