I carried two magazines of HyrdaShok in a 5" 1911 for four years. I'm one of those guys who keeps their gun pretty well oiled with CLP all the time, so the primers all had oil rings around the joint of the primer and case. I would put a round to the bottom of the magazine once it was darkly discolored and the HP mouth was knocked around a bit from re-chambering. Never had a problem with bullet setback (verified with digital micrometer) or failure to fire. I recently shot this ammo and had an average velocity of 900 fps with a SD of 7 fps. Pretty good stuff, and I put 17 rounds into a 4" group at 25 yards from a bench.
Take from that what you will, but it seems to me that worrying about ammo longevity may not be as important as some think.