How about 40 to 50 grains for 2000 fps?
I don't have Trailboss. I don't have XMR 5744.
I have some IMR-4198 (and some RL-22).
I've used a 375gr. cast, 44 grs of both either I4198 and H4198 and both did around 2,000 fps in BELL cases.
With 50 grains IMR 4198 at 50 yards this morning, got 1900 fps and a nice half-dollar size triangle. This with 350-grain RCBS cast bullet from Western Bullets. Tried 40, 45 and 50 grains in three shot groups. (FWIW, 45 grains gave 1750 fps.) I may stop there or try 55 grains, but that's it.
Cheers!
Did you get any hangfires or wide ES?
My loads also used 12 grs. (measured) Dacron filler, hitting your requisite of 2,000 fps, or thereabouts.
Even at 2,000 fps, those loads may be at the pantywaist level pressure wise, but they still shove, don't they!
My other reason for the Dacron is it allowed one hole accuracy for numerous rounds in hot weather.
Its a PITA, but pays for 100 yard groups and sustained fire. If looking to just plink with a gun that's too expensive and not "fun" to shoot, it looks like your there!
No worries -- except now I think I have a bug for Christmas.
(I shoot 'em atop the bench and two seats, standing, with PAST.)
Used Christmas money to buy long sleeve T's without anything to do with ducks on 'em. If I grow my facial hair and act all reality and junk, can I have a show called "Kudu Kommandoes"? I'll promote cast boolits and shoot my .416 Rigby a bunch. (LGS has lots of IMR 4139 now.)