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).

55 grains

I appreciate it!

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!

Remember to flare the case mouth before trying to seat gas checked bullets. Mine were already slightly open from when I pulled some seated 400-grainers. Even so I buckled the first one. Bought a Lee universal case expanding die from LG Outdoors in Montgomery, AL. It was actually sitting at my door Christmas morning and I used it on some resized fired cases I'm getting ready. Barely reached my .416 Rigby when screwed into RCBS press. A slight touch "belled" them nicely and I'll see how it all goes next round.

Doubless clued me in to that.

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.)