I'll usually try to keep at least 500 rounds or so of my favorite load ready for action when I need it.
I load more 357s than anything else, and will generally load up 500 rounds per session. Sometimes, when I'm not quite up to the task, I'll get 500 cases ready to load, then charge, seat bullets, and crimp the next day.
This is all on a Rockchucker, so it gets right tiresome at times. I desperately need to move up to a good Dillon, but I'm just worried about how consistant my loads will be if I roll out ammo at such a blistering pace. I shoot a lot at longer ranges(200 yards or more) with my Marlin 1894C 357 magnum, so consistant loads are a must. Just a little difference in a crimp, or powder charge will definately cause a miss high or low at those ranges.
It's not uncommon for me to go through 500-1000 rounds of 357s in a week with my Marlin, and my Blackhawk combined, so I definately spend a lot more time loading than I do shooting.