.648 tumbled round balls shot with out a patch.from my smoothbore prior too reconfiguring the barrel..
Benched , front sight only & tang screw slot.
The shot low and left is where the gun shot at 25 yards with my point of aim on the bullseye… prior too flexing the barrel.
The other 4 are using Kentucky windage for adjustment.
My bore measured.653. A .642 ball shot ok too..
I have since found a patched .626 ball works well , so I no longer shoot bare ball..
But it seems the closer the ball is too bore size the better it shoots, shooting bare ball.
One other thing too mention is the bore fouls quickly without a patched ball being seated.
The lead doesn’t seem too scrape away at the fouling like a patched ball..
Therefore be careful that you swab as needed…
Getting a unpatched ball stuck can ruin your day… unless you’re prepared for it.