i load for accuracy in my colt h-bar. some of my loads with target bullets will group one ragged hole, most loads with hunting bullets will group about an inch.

but back to the original question. for the most part, load data can be used for most bullets of a given weight. but i say most NOT all. bullet construction can have a big effect on pressures. i think it is in speer's manual that has different load data for the same weight bullet. an all copper bullet, or a solid, or a bullets with a partition are supposed to be harder to push down a barrel. i dont have data for all copper bullets, but i have read that the data is different. look at the disparity between manuals, some charge weights vary by a considerable amount. i have also loaded ammo with data from IMR's website and had signs of excessive pressure with a load that was no where near maximum. i double and triple checked the data, the load was within limits. but i still had primer cratering, sticky bolt lift, and poor case life. bottom line is, pay attention to what the brass and gun are telling you.