I have a smokeless barrel for my encore made by SMI (smokeless muzzleloader inc) made in upland Indiana, this thing is a tack driver. I use 65 grains of H4198 with hornady XTP 45 caliber bullet and a black sabot.
I have a Woodman Patriot muzzleloader 45cal which is rated for smokeless at 45kpsi. It’s a wonderful light hunting rifle with 209-primer type ignition. Typical load is 62grains Reloader-7 with 275grain non-sabot (smooth sized). That’s a reasonable hunting load at about 2600fps.
But don’t even think about it unless your manufacturer rates it for smokeless pressure