Lets assume that you replace barrels when they wear out. I consider barrels consumables.
Each barrel will be given a new headspace. Any receiver set back, and there will be some set back, will be adjusted for in the cutting of the new chamber.
Due to lack of spare parts there are rifles that are dead in the water once you break a firing pin or extractor. By the 70's, people were having to modify M1917 extractors to use in pre 64 M70 actions, the parts supply for original M70 claw extractors had dried up. I have a pre 64 257 Roberts that had one of these ersatz extractors.
Extractors, ejectors, firing pins, they will break over time. They can be replaced for your rifle as there are still M1917 parts on the market.
Even if a bolt lug cracks you can replace it.
I believe the mechanical lifetime of your rifle will be determined by the receiver. If and when it ever develops cracks.
If I'm not shooting, I'm reloading.