I loaded some up yesterday and took them out for a trial.
5.6 gr Trailboss.
I crimped the balls, (lubed with Johnson Paste wax), in tight at their circumference.
It was a very modest load. Zero blast or recoil. Accuracy was very good at 30'. A good deal of fun to shoot.
Empty hulls showed signs of low pressure, sooty with powder residue.
I think I will try a batch using 6.1 gr of Trailboss as JBar4' suggested.