Great question and NO! I gave up on fillers years ago.

Accurate states emphatically that no fillers should be used with 5744.

I might add that the goal to obtain same zero was met at 100 meters {300 gr/2450 fps, 220 gr/2450 fps} when the forestock was bedded with strong upward pressure on the barrel {the way my SAKO came form the factory}. Subsequently, after 20 years and a bunch of abuse, a reblue, etc, the gun developed some bedding issues {not related to this 5744 testing} and I freefloated the barrel, bringing back most of its accuracy {it has had 2000+ rounds thru it}, however...with freefloated barrel, the zero of the full-power 300 load is not the same as the 220 download. I think a little tinkering might improve that.

Other bullets can be used with 5744; heavy or light, jacketed or cast. I believe a ".375 Winchester/Heavy .38-55" load could easily be worked up with this powder.

I've had good success with 2400 in the '06 case {without filler} but when moving to the bigger cases 5744 is the way to go IMO. I think it would be a real winner for some of the big NE rounds, especially in singles where regulation is not an issue.

5744 was developed for the bigbore blackpowder crowd, and loads are available thru Accurate Arms/Western Powder for BP-velocity duplicate performance with the cleaner-burning, lighter-kicking 5744.

I do not believe full-speed Nitro Express performance can be reached with acceptable pressures using this powder, but I could be wrong there. But with the .375 H&H Magnum, really useful "9.3x57-to-.9.3x62"-equivalent loads are waiting for anyone who wants to give it a whirl. For USA hunting of deer, black bear and pigs it's hard to think of better-performing rounds. Light kick and very deadly. Sierra 200's, Hornady 220's and 225's and Speer 235's would all work very well I do believe.