if you reload, use a hard lead bullet like Oregon Trail Laser Cast bullets. i have used no lead but these for years with no leading probs.
drop one of these on a hard surface and it sorta "rings". drop softer lead and it goes "thunk"
years ago, i read an article that said .45ACP military hardball would wear out a barrel in 30,000 rounds. if that is true, lead would go on and on and the difference in cost would buy the best barrel on the planet, custom fitted. gunk buildup is usually a powder problem, not a bullet prob.
then, scrubbing a barrel vigorously with a bronze brush will contribute to barrel wear also.
all the above applies to precision shooting. for general use, i dont think you are gonna wear it out with whatever bullet.