I just bought a Triditions Tracker 209 and looking for the best powder to use. I was thinking of using American Pioner.

pyrodex rs or triple 7.

It is hard to find in some areas, 777 is available everywhere. If you have a stable source, I would say use it. Less crud ring that 777 and very clean. Absorbs moisture more than 777 is the only thing I know against it. Oh, more costly also.
Chap Gleason

I found that American Pioneer Powder works fine if your shooting sabots and they are not too heavy. If you want a more consistant powder, then tryPyrodex RS. Although Pyrodex is a dirty powder, very few rifles will not shoot it well. Triple Se7en might give you a hard crud ring. You'd have to try it and find out.

I just bought a pound of American Pioneer 2f powder. I want to test some sabots in a few rifles with this powder and see how hard I can push them.

The one thing I will say for American Pioneer powder is, there is little to no fowling and clean up is easy.. Good luck with your new rifle.

APP is my favorite. I don't know how that gun would perform with it but mine shoots awesome with it.

You should probably just test them all and use the best one for the gun. Pyrodex is the most economical.

Try pyrodex triple 7. It is one of the cleanest burning.

The problem is with the 777 is there is a crud ring at the bottom of your rifle and you sometimes has to push down hard to get thru/around it. That is why I always field clean in my rifles with 777. I like the way it shoots with 15% more energy than BP. I use loose now, not pellets. Use to use pellets, but learned how to use loose in FL so use loose in every rifle now. Chap Gleason