I know there are a couple of gunsmiths who frequent these boards who can give you an expert answer.

However, there are a few things you can do (and avoid) that will prolong the life of your current barrel:

1) Heat is your enemy. Anything you do to create more heat than the barrel can effectively absorb or dissipate invites damage, and not just to your barrel.Heat comes at its worst when your sustained rate of fire is too high (i.e. "blasting away" at targets).Mitigation is pretty obvious. While you do have the ability to sling lead quickly if you need to, most occasions won't require it. One, maybe two rounds while hunting. If you're at the rifle range practicing, keep your sustained rate of fire down to what you might with a bolt gun and give your rifle a break between magazine swaps.

2) Maintenance. This one ought to go without saying, and the bore isn't your only concern.