John Johnson's powder review in the summer Blackpowder Hunting magazine included AP powder, it provided the the least velocity of all powders tested, some by a large margin, but shot the cleanest with very little residue left in the barrel after shooting. Using 65gr of FF powder in a round ball gun shooting 4 shot strings, average velocity for the powders tested was..
Goex............1255fps
Swiss............1638
Schuetzen.....1347
Triple 7.........1518
Pyrodex RS...1292
Pioneer.........1045