In my experience, in particular with 30-06 cases, if they are kept annealed and just collet-sized, there hasn't been a need to bump shoulders back, and have never experienced problems with case stretch to the point that the bolt operation was hindered. Some of my brass has been fired a couple dozen times and annealed at least 6 times.
In general, because I prefer to just collet-size, if a round doesn't chamber easily, I know it's time to anneal.
But that's just how I do it. I avoid Federal rifle brass, except the military stuff, unless I'm loading cast bullets. Soft case heads and loose primer pockets directed me elsewhere.
