Even jacketed bullets don't wear out a rifle bbl when shot at high velocity, let alone lead at low velocity!!
Sorry, I disagree. Jacketed bullets DO wear a barrel, especially at high velocities. 220 Swifts and 223 WSSM are known for eating barrels. Lead bullets wear a barrel, not as fast as jacketed bullets. Muzzleloaders using a cloth patches wear barrels. Paper patched bullets are probably the worst, unless you talk about shooting tracers.
Just FYI.....cleaning your barrel with those soft cotton patches causes wear.