I answered the Foster slug, believing the weight of the 12 gauge was more than what it actually is. If I had done a little home work beforehand, I think I would have picked the mini ball. So, up close, the slug, out farther the mini.
All of the below is from a You Tube video, and a brief look about the slug on the 'nett.
weight of the Foster slug is approx. 1 oz. or 437 grains
1600 fps at the muzzle- but they loose energy very fast
the video stated the foot pounds of energy is 2,484 (I assume this is at the muzzle)
Close up, (50 yds or less) due to the slugs large frontal area, wound damage is pretty massive ( these slugs are a hollow point design, so their transfer of energy would be pretty effective). See the wound cavity in ballistic gelatin here-->
But, due to their inherent lack of accuracy (they start to tumble past 50 yards or so), and loss of energy, makes their stopping capability much more suspect out at 100 yards.
The mini ball would not have this problem at these ranges. A video of the effect of a 58 cal mini and a 54 cal Lorenz bullet here-->
Keep in mind that the muskets have been down loaded to approximate the energy at 100 yards.
This video shows the approx damage done with a full powder charge at 20 yards-->