Some say yes others say that they should not . Shotgun barrels are made so that the barrels tubes come together at the muzzles . Centers at the breech varied so the convergence was never a real consideration .
You can work it out mathematically by taking the centers at muzzle away from the centers at breech and dividing that by the length of the barrel to give the taper .This can the be projected to find the cross over point . In my experience experimenting with lasers at 30 yard the right barrel will shoot to left of center and the left to right of center . To make a pair of shotgun barrels that have over lapping patterns at 30 yards the barrels at the muzzle would have to be spaced about 5/16"to 3/8 "on a 28 inch gun dependent on the center at breech .