My old .17 barrel likes to shoot clean. My barrel had about as many rounds through as yours when I got it. Rustydust gave me some good tips that got mine shooting good.
First get some JB bore paste, "the abrasive kind" and run about 500 passes of the stuff through her. Clean with your bore with good copper solvent. Shoot a few rounds and see if she is fouling up and given flyers. If the copper fouling goes away and your still getting flyers, you might want to bed your rifle.
I had some trouble getting good chamfer and getting bullets to stay straight while seating. Russ said the lyman VLD chamfer tool would cure it, and sure enough it did.