A year ago I went to the range and returned home to a Divorce. I didn't clean out my barrel and the gun sat in the safe since, which is in her house. I got the gun last week. Looked at it today and it's pitted from the breach to about 5 inches from the muzzle. UGH! I cleaned it as thoroughly as I could. I went to the range today and shot it about 20 times. My best load gave me 1 inch, 4 shot groups at 100 yards. Today, the best I could muster is 4 shots in 3 inches. This is still respectable for a hunting rifle. I guess I'm just wondering how the pitting will affect the accuracy over time. If I clean it like I normally did, should I expect the 3 inch groups for a while or will it degrade quickly? I didn't see any sabot material while swabbing between shots.

Please keep bashing to a minimum as I already feel terrible. I guess the silver lining could be my need to buy a new barrel.

Well you can try to get the pitting out. But you might not get the kind of accuracy with it you were used to. Perhaps it is time to get a new barrel for it, or a new rifle.

First off it should not degrade if you keep it from rusting any more. Second if you do a good careful lapping job or have one done it will improve but you will have to use a larger diameter combination of sabot and bullet. Third if you don't know how to do a lapping job be sure you find out first.
AND BEST if you send it in to TC [call them first ] and give them an accurate description of what happened they are liable to fix it for you and they do a really good lap job. Lee