montveil I can not be qualified near to being an exert on BH-209, I have expermented with a couple of bottles - shooting it in all of my different inlines... I can tell you that it appears to be accurate, it does solve the patching problem and it is slightly faster than T7 or Swiss.
BH has engineered to be a BP sub, but if you were to get a government MSDS sheet that spells the ingredients you would find it is a progressive burning smokeless powder - not using NCell - but one you open a bottle you will get the unmistaken smokless odor ether. It is not hydroscopic, it matches BP volume measurements and shoots with the relative same velocity and with less pressure than T7 (according to Western) and that is entirely possible since it is progressive. Where it walks away is with the heavier bullets that stay in the barrel longer and allow the powder to really be efficient.
In each of the different rifles I shot it in a White M97, a Remington 700ml, a Knight Extreme, and a Omega with a 25 acp (with #450 primers) it would produce approximately 100 ft/sec faster velocity than T7-2f and the POI @ 100 yards is esentially the same. All of these were shot across the same chrono.
Toby B has completed a comparison that might interest you, but again remember he write these reviews for compensation, although I find this comparison fairly accirate with my experiances...
http://www.hpmuzzleloading.com/SpecialReport2.htmlI should have also added, the cost of 10 ounces vs the cost of 16 onces of T7 makes it to expensive for me to shoot. I could further qualify that by saying if I were just shooting it during hunting season - it would be my powder of choice - but I really like shooting ML's way to much...