Daryl;
The REAL problem which nobody has addressed here, is regulation. Carlson, or any other smith, is going to ream and thread the muzzles to accept their rifled choke tubes. Assuming that you mount rifle sights on the gun, it will then be a simple matter to get one or the other barrel to shoot to the point of aim. However, the odds of BOTH barrels shooting to that point of impact are slim to none. If they DO, I'd suggest that you run out and buy a lottery ticket for one of the big ones like Powerball or El Gordo because it would certainly be your lucky day!

Best,
Ron.