according to old ed the gunsmith, a technique that works quite well is to braze the ribs and barrels together, except for the last few inches at the muzzle ends, which are then soldered together after the barrels have been regulated. he recently sleeved a parker for me using this technique with fine success. the gun shoots both barrels to point of aim at 35 yard! quite an accomplishment for someone over the age of 80! i also understand one of the reasons ruger stopped making sxs shotguns, is because they could not work out a method to reliably and efficiently join the barrels and ribs. ed1

keep it simple and keep it safe...