I know alot of people use JB bore compound but it is a big mistake unless your rifle is badly copper fouled.Lapping compound used in a new barrel can be a mistake the lapping compound can round the lands in your new barrel which you want to keep nice and sharp.I have had people bring me rifles that used JB so much that they ruined the rifling in the barrel.If you use it be careful!! I will not ever put JB compound in any of my rifles.