Ummm, if everything fit perfectly... probably, but I don't really know. If the pellet were the exact size of the inside diameter of the case, and the bullet seated tight against the pellet, I don't see why not. Loose filler couldn't be used without a wad to keep it out of the hole in the pellet, and the pellet would have to be the exact size of the inside of the case so there was no dead space between pellet and case. I'd stick with loose, powdered pyrodex or black powder if it were me.
Sometimes the squeaky wheel gets replaced...