Measure your actual bore diameter. Then because this is a smoothbore, you want to pick a ball diameter that is .020" smaller than the actual bore diameter, if you intend to use a PRB in the gun. If you want to just shoot a bare ball, then you will want a ball that is within .005" of the bore diameter. You can use a wad over the power, or OP WAD, and then an OS CARD or two over the ball to hold it into the gun barrel, and keep it from moving. Some use TOW, which is usually made of flax fibers, both to seal the powder and gases behind the ball, and to hold the ball in its place on the powder. Generally, the closer you can get a ball to the size of the bore, when shooting it bare, the more accurate it will be. With a large ball like a 12 gauge, made of pure lead it will be soft enough to upset and fill the bore even fired bare.
I do not recommend shooting balls bare, because of the leading they cause in the barrel, the worsening accuracy you get for subsequent shots when the lead streaks batter, and remove even more lead froms subsequent balls fired, as well as allowing a break in the seal of the OP WAD that permits gas to blow by and cut your ball, and the devil of a time you will have getting the lead out of the barrel. A ball .020" smaller than bore diameter, with a .015" thick cloth patch should provide a tight fit of the PRB in your barrel, and give good accuracy.
Go to the Member Resources at the top of the Index page to this forum, and scroll down to Articles, Charts, and Links. Click on the Charks, and you will find some way down a listing of Stumpkillers Moose Juice and Moose Snot recipies. Make up some Moose Juice using the formula, and you will be happy with how well the combination works in your gun. Or make up the Moose snot solely as a patch lube, and use it on patches. Moose juice can be used both for cleaning, and for a patch lube, but should be used on a range where the shot will be fired rather quickly to avoid contaminating the powder charge with the liquid. When hunting, you are better off using Moose Snot, IMHO.
