[arcticap]

One thing that you can do when cleaning it is to run a tight lubed patch up and down the bore to check if the bore is ringed or bulged. That happens when a projectile is short started instead of being properly seated all of the way down on top of the powder charge.
If you notice any loose spots inside the barrel then there could be a bulge or barrel weakness. Usually it only affects accuracy but if there is any slight bulge, then barrel replacement is in order.