1680 really sucked in my .221 with 40-grain bullets, but shot OK with 50's. But I didn't do any experimenting with primers, partly because Li'l Gun worked so well.
One thing I've noticed while discussing the .221 with other shooters is individual rifles seem to prefer RL-7 or Li'l Gun, but not both.
In the .17 Fireball I got such outstanding results with TAC (the first powder I tried) that I never experimented a vast amount. Benchmark, 8208 and H322 also shot well but not any better than TAC, and TAC metered easier through the little neck.
