The folks who run APP have not been helpful at all. For years APP told shooters to seat the bullet/sabot hard on the powder.
IME: All the APP powders require compression to work well. If you do not heavily compress the powder the sd will rise and accuracy will go to pot. For best accuracy it is necessary to seat a tight fitting ball or sabot very hard on the powder. Place a drilled golf ball or furniture knob on the ramrod and compress the powder. i also whang the bullet once with the heavy ramrod.
An old ballistician and myself used his very sophisticated and expensive equipment to test JSG, Pinnacle and Black MZ powder. One session with Black MZ powder gave an sd pf 17 fps. Highest sd was about 40 fps.
The lawyer/s at APP grew concerned that someone would get hurt while loading. They tolds folks to not compress the powder. Then they "warn" folks not to use bullets over 250 grains when firing their JSG Super Powder; go figure.
The folks at Alliant Powder tell shooters to heavily compress Black MZ powder.
Black MZ functions best when heavily compressed by the seated sabot.
http://www.alliantpowder.com/product...r/blackmz.aspx
i'm not concerned with the larger granules of the APP powders. JSG, Pinnacle and Black MZ work very well in conventional muzzleloaders that are properly maintained and loaded. After the powder is poured lean the gun with the lock side down and give the stock a whack or two with the hand. That will allow powder to enter the flame channel or bolster.
All the APP powders are ascorbic acid based: So was Black Mag 3. Ascorbic acid based powders will deteriorate over time. i had a few cans of Goex Pinnacle go bad. The stuff fired every time but the puissance was not there.