I propose more barrel "wear" is caused by powders than bullets. Notice that the handguns barrels mentioned in this thread as being worn were worse at the frame end than the muzzle. Bullet is traveling fastest at the muzzle people. Hot gasses are blasting the part nearest the chamber. Guys offer get flame cut forcing cones and frames. What makes anybody think it stops at the forcing cone ? Had a 220 swift. Accuracy fell off. Barrels erosion in front of chamber. Muzzle was fine, bullet was moving at 4200 @ muzzle, not at chamber lead. Powder scrubbing. . Which powder you run can have as much or more effect than bullet. Plus I bet it is far more likely that a lubed lead bullet has a bit of dust etc than a dry copper jacket.