I bought my son a CVA Wolf several years ago. The gun shot great until this year, I had cleaned it and put butter bore in the barrel while it was stored. Went to sight it in for this season and after it was cleaned and there were two "hard spots" I call that because when I was loading the sabot it came to a complete stop like it had hit the breach. Nothing I could do aside using a brass hammer to tap the ramrod down. I shot the gun and it was right target from last year, I thought leave well enough alone, but I tried to lode it for a second shot and the same thing happened,the ball just stuck there and no matter how hard I tried to push it down it would not go. I'm a pretty strong guy and I still had to use the brass hammer. I cleaned the barrel, scoped it and could not find any fowling in it. What could be wrong?