I had a 500 turkeywith the ported bbl andforest camo .It looked as if the powder coating was on the inside of the bbl too . I scrubbed it up alot . The gun shot ok and where it was pointed . I sent a letter off to Mossberg . I bought the gun 7/27 inNovember I went to see a gunsmith and tookthe 500along he looks at the bbl says "I can polish it out but if you shoot it some it'll clean up , Faster with steel ". At that point I had put 100-150 rounds through it and picked up a Hastings choke for ducks ( it came with imp/cyl and maximum turkey ) half of which was steel . I sold the 500 in July of 02. I still don't have an answer .