I had the same thing happen last weekend..I polished the barrel took it to the range and the first shot of 3 inch 5's put 175 in a ten ring..at thirty which was a big jump from the 140 counts that it used to throw,I took the barrel off and cleaned it and choke and sent another one down range and it was terrible..was scratchin my head..went back in cleaned it again but didnt tighten the crap out of the barrel that time and pounded the target for the next three shots..I think I had it to tight!...Think that after I polished it that she became a little picky