Why no Trail Boss??

[The Heretic]

Dacron is inexpensive, generally hold the powder to the rear and in one position, burns and is expelled, adds very little weight to the charge and leaves no residue.

I have used it as a filler on top of Bullseye.

Just the same, I do not use very small amounts of slow powders (relative to the starting recommended charge). I am looking for loads that will be subsonic or near that speed.