Bore Slugging
Hello,Barbre. You don't say what you are loading for, rifle or pistol. I have a few boxes of left over Speer round ball in various diameters. These are nice and soft & make good slugs. Clean bore, & run Very lightly ouled patch thru. I generally put a drop of oil on fingers & rub ball with this. I use a rawhide mallet to start ball into muzzle...DO NOT use a steel hammer!..You will be saying very bad things for a long time if you do! Once it's flush with muzzle..might even be a small ring of lead peeled off ball. use a brass or wood dowel to tap ball through bore..feeling for tight & loose spots. Carefull catch slug in cloth or hand to prevent denting. Use a micrometer..calipers..even those fancy dial or dig. types are not accurate enough. Now getting back to the dowel..some of those you find in hardware have cross grain & can split & break. If you can find a muzzle-loading shop they will have good hickory ones. For smokeless in rifles, I like to go from .001 to .002" of inch over groove dia. In my .40-70 Sharps with a .408" groove, I am using .410".
Sometimes you cant..in my original .38-55 Win. High-Wall groove dia. is
.379, I can only use .380..and this with a polished out case neck, because of the way these were designed for black powder. In my .22 Hornet, groove dia. is .224, I am using a gas-checked cast-bullet of .226 dia. If you can't find rawhide mallet..a plastic one is ok..just make sure face is clean.
Now as I said, you didn't say what this was for. Now for revolvers..Thats a whole different ball game. You should slug your cyl. throats & choose a dia. that can be pushed through with a little bit of resistance..not pounded thru, but not dropping either. If throats are greatly over groove dia..some compromise or a new cyl. might be in order. Best of luck!