Further to my post above, I'll add this.
I bought a Lee R.E.A.L. bullet mould for my .45 rifle just to see how they shot in the 60" twist 42" GM .45 barrel. The Lee mould was for the lighter 200gr. R.E.A.L. bullet. Lee also makes that design in a 220gr. weight in .45 cal.
I fired 10 shots with them, using Lyman BP Gold lube at a 50yard target using 75gr. 3f GOEX. The bullets struck the target some 2 1/2" low of the point of aim. The accuracy was fair, as I ended up with 2, 5 shot groups of approximately 2" each. They were not as tight as this rifle does with patched round balls. I had no difficulty in loaded them - easy is the best way to describe the loading. I do not know if they would maintain stability after impacting an animal - might be ok for small game like a deer or smaller black bear, but I would not use them on elk or moose. You need a stable bullet for straight line penetration on large game. The rifling twist in my rifle is just to slow to accomplish that task.
After shooting the 10 shots with the bullets, I loaded 75gr. of 3f GOEX and a .022" Lehigh Valley lubed, patched round ball and fired that. It struck centre. I finished off the day by shooting a number of 3/4" to 1 1/2", 5 shot groups at the same 50yard range - never having to wipe the bore, during ALL of the shooting, that day.
Whatever fouling was in the bore after the first 10 shots with the bullets, was removed by the loading and first shot with a patched round ball.