I was surprised at how well a 24", 1/48 inch twist barrel would shoot a sabot and bullet. But I bought the rifle to shoot patched round balls. I just haven't had time to figure out the right ball, patch and powder combination for it yet. The sabot, bullet and powder combination was easy to find. I went to a buy some powder the other day at a store that Hornady's web sight said carried their .535 caliber round ball so I could try them instead of a .530 caliber and they said they didn't have any round balls at all. I have already cut some blue jeans up for patches to give that a try and see if they will work with the .530 caliber balls. My next purchase will probably be a slow twist .54 caliber Green Mountain barrel. Then maybe a .58 cal.
I have to admit that I am getting a little board with the .50 caliber and I am looking forward to playing with a .54 caliber.
Tradition's Rifle Company has discontinued making the Deer Hunter in .54 caliber. The price had come down to sell them off when I bought mine.

I love my Green Mountain 54-120 Brush Gun. Best $400 i ever spent on a ML and one of the rarest i own.

54 was and still is the most popular caliber for PRB because it is the longest range flatter shooting with the enough fp of energy for most American game with a wound channel that leaves a good blood trail.
The 50 caliber is poplar in inlines because it works well with 45 and 44 caliber bullets which means a wide choice of bullets and sabots, and maybe 50% greater range for most people.

That depends a lot on what region of the country your in. I would be willing to bet that the .50 has at least a 5:1 lead over the .54 for rifles being used during our late ML (flint only) season here in Pa. Nothing against a .54, I have them and use them. It's just that the .50 is much more commonly used here.

BPS

I have three 54's 2 Lyman and a CVA ST Louis Hawken also a GM 32 inch smoothbore 54.