I am going to work up a load for my 500 S&W Big Horn Armory model 89 carbine. (18 in barrel.)
It will probably be Lil Gun or AA 5744.
My goal is to get as close as I can to 2000fps.
Anyone have experience with this bullet?

https://www.lehighdefense.com/...gr-bullet&search=500

Hodgdon CFEBLK is worth trying for 500S&W rifle barrels, especially a single shot, where you can seat the bullet shallow for more powder room.
See Hodgdon loading guide website. Shows only pistol barrel loads but it gives you an idea.

Marty, I have a WSM, 1.8" 500 cal rifle. Best performance is with 300 MP.
Alliant has a recipe for 350 grainers.