THIS ^^^^ PLUS 1That's either dried out lube or oxidized lead. They look good to go for chooting, but wash your hands.
....but wash your hands.
Ive bought several old 22 rifles over the years that had all the rifling filled with lead. Smoothbore is right. Takes alot of scrubbing and cleaning when they've went that long without cleaning.That stuff gets in the grooves of your barrel. Shoot enough and you have a smoothbore