Odd man out, here.
For sheer mind-splitting velocity, I've always liked IMR-3031. But that's under 50's and 52's. Might need to slow the burn rate some for 55's. I just got such great results from 50 B-T's and 52 Horny HPBTM's that I never ever tried 55's or heavier.
I'd probably have paid for it years ago with a fried out throat if I had time enough to shoot the gun lots. But I don't. So it's faring very well, thus far.
