Free: Contests & Raffles.
the goal is to powder/carbon fould the barrel before the copper fouls it. there is a bunch of ways to skin that cat.
There are about a 100 ways to do this, but if you haven't done a lot of large centerfire rifle shooting/cleaning just remember not to whack the handle of your cleaning rod on the crown of your barrel when you clean it. Get a ding on your crown and you may as well go buy a new barrel.