A lot depends on the type of ammo you use. If you use light target ammo with cast bullets, the lifespan will be much longer. The 500,000+ figure for some of the 1911s seems very high unless that 1911 is being used with light target ammo. I don't think they'd get nearly that many rounds if using full power jacketed 230 grainers. If that's being too pessimisstic, I'd sure like to see some evidence that they will shoot that many rounds before replacement. It would be great if they could. In any case, I'd expect to replace barrels within 20,000 rounds.