HI Y'all
I have a smoothbore Musketoon by Parker Hale. The current production is built in Italy and the one I bought was .56 NOT .58 as marked.
I use a pistol range of 25 metres and 40 grains is enough and accurate (for a smoothbore) any more and you are wasting powder.
I fire .565 dia.spherical ball -- I had to get a mould made. I use patches of .007" thick cotton. so it fits well in .58cal
Gogs