Hmm, the reason I was following this thread was for a specific reason not just hammers which is on my list of have to try bullets. As for as the monolithic and copper jacketed bullets is it wear or is it copper fouling that is the most problematic issue on your barrel accuracy, barrel life? Most folks here shoot a lot more than I do, it is always good to get an opinion. Albeit everything I use is copper jacketed or mono bullet. I am of the opinion that both bullet types will wear a barrel similar fashion. The reason for my question is having taken days to clean a heavily copper fouled barrel, which brought accuracy back to acceptable, I was just looking for a rough rule of when I should budget for a rebarrel of a rifle. Three magnums rifles loaded hot, 4 non magnum rifles. Thanks, James