THANKS, I am wondering how much oversize the lead slug/ball needs to be? I may have to take my calipers into Walmart and measure some fishing sinkers.
Later, Tom
Skip the fishing sinkers. They're too hard. Just squeeze a soft lead bullet slightly so it is deformed, lube it, then tap it in the muzzle but leave the end sticking out. Pull it out with pliers. That is your muzzle dimension. Then drive another slug through the length. Feel how it glides through. It should be the same throughout.
On a gun with 5 grooves, you use a strip of soda can wrapped around the bullet so it covers one groove, then measure. Yours is 6 groove so there is no need for that added step.