Buy T/C bullets for your Encore. The T/C Shockwaves are brother to the Honady SSTs. In 200 & 250 grain, they load easier than the SSTs in T/C bores. Hornady bullets fit the wider-bore Knight Rifles better. In some instances, the SSTS shoot well in T/Cs... but most are real tough to load... requiring a few grunts & some strength.

OK, I use a 209-50 Encore as my primary deer gun. I have shot and will continue to shoot it a lot. This is what I have found to be true in MY gun, using 295 gr. PowerBelt H.P. bullets Yours may not act the same.
2 Pellet: Much more accurate. (1 1/4" at 100 Yds) Less Recoil. Enough velocity that I have never recovered one in a deer. Exit hole about 2" in diameter.
3 Pellet: 2 1/2" groups at 75 yards. Significantly heavier recoil. More expensive to shoot. Higher velocity should equate to longer range, but in my gun the lack of accuracy with the 3 pellet load kills that theory.
Well, this is what I have found. Good luck, and I hope this helps

Will be receiving my first experience with black powder shortly in the form of a 209x50 Encore.
Plan on experimenting first with Hornady 250gr SST sabots probobly with 50gr pyrodex pellets.
Question being is there much loss of velocity by using 2pellets=100grs verses 3pellets=150grs.
Is it true most times added accuracy is noted with 2pellets and that 3pellets have a tendency to blow out end of a 26inch barrel with negligible velocity loss.
No doubt will experiment anyway and may even try some non-pelleted powder forms however on hands experiences from those who have actually done this before is very important to me and most appreciated.Im finding this to be quite differnt than the normal centerfire rifle reloading thing.Thanks to any response.Plainsdrifter