Yeah, I've been experimenting quite a bit with both IMR4451 and 7977 lately. They're not on all store shelves (though they're showing up more and more), but just about every Internet site has 'em, and even with the hazmat shipping fee a jug can be purchased for a per-pound price that matches or beats most store prices these days.
IMR4166 is another good powder, with a burn-rate close to IMR4064, but that means it's also in the same basic range as TAC, IMR4895 and Reloder 15, all of which seem to be pretty available now. But IMR4451 and 7977 are definitely filling a need.
