Yeah I use 'em both quite a bit.
Bullseye and AA#2 are both fast powders . . . and that's where the similarities end.
Bullseye is fast for a fast powder. AA#2 is slow for a fast powder. Quite a bit slower. Both however, are great propellants for 45 ACP. There's lots of "crossover" where either powder will work for the application. But there are some things that one is better at than the other.
If you load real light or "pure target," Bullseye is the better choice. If you load with a little bit of punch - "range ammo," like Winchester White Box - you'll do a little better with AA#2. But either will do either. Basically, AA#2's smidgen of "slowness" does progressively better than Bullseye as you move up the velocity scale.
Bullseye is "residuey." AA#2 is very clean.
Bullseye meters fair. AA#2 meters superior to anything I've ever used - bar none.
Bullseye is more economical; but just slightly.
Really, with 45 ACP, you can't go wrong with either. You mentioned 9mm? If I loaded for both chamberings, and had both propellants, I'd use Bullseye mostly for 45 ACP; and AA#2 mostly for 9mm. AA#2 has a slight preference for the higher pressures found in 9mm. AA#2/115's in 9mm is a phenomenal combination. Much like Bullseye/230's in 45 ACP
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