Assuming the parts were proper spec and installed correctly, and assuming the barrel is not over-torqued, and assuming ammo used is within industry spec, you should be good to go for a long time. My shooting friend keeps a record book with each firearm. His Model 38, acquired new in the mid- to late-sixties, now has 18,000 rounds down range. No issues. I would say that the only issues you might experience after many thousands of rounds would be DCU (doesn’t carry up); or, if you’re using +P, which is totally safe, but which will accelerate wear, you might eventually experience end shake. Both conditions are easily and quickly corrected by the factory. If your 442/642 uses aluminum pins, you may experience a bent one. Again, the factory can take care of this.