I wonder how it'd do with good round ball loads - smokeless and BP. The penetration would be better even with pure lead and especially so with WW balls. The .690" ball (Lee mould) held in the base cup (to centre it) of a trap wad, along with requisite wads to fill the space will attain upwards of 1,600fps. The .690" ball will run about 500gr. Too, the Lyman sabot waisted slug that fits in the shot cups might be another heavy penetrator at 506gr. WW and 525gr. pure lead. They will run out up to about 1,400fps.
: Check Lyman's loading manuals for data.