Hi Gary, yeah I used a boring bar to get it to the right diameter. First I used a 1'' drill bit to drill down to the depth (the bottom of the powder chamber) and then I used the boring bar to do the rest.
Powder chamber measures 1'' x 1.125'' so should give me plenty of room to experiment with different loads.
Willie, how would you do a 6 pdr or 12 pdr? Bigger drill? Longer boring bar? I'd be worried that the length of the bore would cause flexing in the boring bar.
