Another gun ruined by those damned choke tubes! Unless they are factory installed, I wouldn't touch a gun fitted with them. They, ported or backbored barrels, are all inventions of the marketing departments. As Adolph the old German gunsmith at Abercrombies in Chicago used to say: "Aaaach! You tink you make a better gun than Remington or Vinchester!? Get out my shop because I von't help you to ruin a goot gun!" Buy spreader loads if you need less choke. Once you rebore a gun you can't put the metal back. Chopperlump