In two years of PPC shooting, I put a documented 50,000 rounds (by actual primer count) of .38 Special lead bullet loads through an M19, plus another couple hundred .357 Magnums. The forcing cone showed a trace of roughness from flame cutting, but the bore was still like new, and accuracy was as good as when it was new.
I guess it is theoretically possible to wear out a bore by shooting, but it is not likely to happen with lead bullet loads.