WStrayer, hold everything. Why the choke tubes for slugs? I have the same .22 mag/20 gauge and it shoots slugs beautifully and only 4" lower than the mag barrel at 50 yards. I've never patterned mine, but I'm assuming that it is probably a modified choke barrel. They are rather desirable guns and messing with the choke will likely diminish the value.

My other auto is a .45

The bitterness of poor quality is remembered long after the sweetness of low price has faded from memory