Jeff,
Slug barrel in the combo will only be a smoothbore with rifled sights, but that ain' t all bad. Guys have been shootin slugs pretty good for years thru those smooth bore slug barrels. I have a pretty short smooth bore 12 gauge J.C. Higgins pump that I can tear up a paper plate at 60-70 yards, shooting while standing.
The real serious end of slugging would be to get a fully rifled barrel with a cantilever scope mount. Then you can really expect to hit out to 100 yards, maybe more. I would only use a cantilever mount because the scope is mounted to barrel and can' t lose it' s zero as barrel is taken on and off.
Jeff Gordon? Isn' t he gay? I heard he was having a relationship with one of his pitcrew. I heard it was the jackman!
Post again. I would be intrested in what you do with barrel choice and what results you get.