The best powder to use for rifle cartridges is the one that most nearly fills the case.
When I first started reloading for my 270 Win I used the Jack O'Connor load of 60 grains of H4831, and it will almost fill a case. Never having done that before, I consulted my neighbor, a long time reloader, and he said that I'd blow my rifle up if I did that. He used a mild load of 4064 in the 270, one that did not come close to filling up a case, and was unfamiliar with H4831. I gave it some thought, and figured O'Connor knew more about the 270 than my neighbor did, and I've used a case full of H4831 ever since.
