I can say beyond a shadow of doubt the Pedersoli, muzzleloading double rifle I had was not regulated in any way, shape or fashion. I got pretty good at regulating old doubles with load adjustments and thought I could eventually get the Pedersoli to shoot 'good enough'. That did not happen so it went down the road. Using two sights, one for each barrel, on a double is anathema to me..

Now, my Baestlein, (German), 56 cal., muzzleloading double rifle from the 1850's regulated with the second load I tried. It was supposed to be a summer long project but came to its milk rather quickly! 2 1/2 to 3 inches at 65 yards, composite groups.