tiny68,
yeah it is all about how fast you want to push them, just gotta find the right combo. i knew what speed i was wanting out of them. i tested h4831, h4350, imr4350, rl17, and i didnt get the velocity i wanted until i worked up a load with n550 and the barrel seemed to crave a max load with it. (stilll no pressure signs, primer pockets are tight when re-priming)