If those really occurred at 50 yards using an open sighted sidelock and roundballs, that's really freaky-good.
I don't quite agree with that
GB, and have no reason to question the target. That appears to be a 3" bull. So the four-shot 50 yard group was about 1.25" and the three-shot 75 yard group about 1.5". That's very good for sure, but not what I would call "freaky good". A good round ball barrel with a proven powder/ball/patch combination should be able to do that on a fairly regular basis
from a bench. Now offhand - it's a whole different game.