Recommended load for Brass framed lever gun in .45 LC?

Looking for some advice on what bullet to use for a Uberti brass framed Winchester 1866 musket replica with a 30" barrel.

What bullet weight and diameter is recommended? (I was thinking about buying coated lead bullets)

I have lots of HP-38 powder I do see various recipes for it in my reloading manuals just wanted to know if I should not exceed a certain level of Pressure in a brass framed rifle.

190 to 260 grain boolit at .454 Ø will work, your HP38 will work also just look up loads for the Colt SSA, DO NOT LOAD anything hotter
as that brass frame will begin to stretch.
I have an 1866 in 44-40 and 45C, I use 3.5gr Reddot with a 200gr boolit in the 44 and a 260gr in the 45C