I have a Stevens 315 SxS in 20ga. The schematic I got from Numrichs shows four available barrels in .410, 20ga, 16ga, and 12ga. It does not list part numbers for recievers.
That being said...
a) Is there reason why I could not swap a 12ga. barrel in palce of the 20ga?
b) Did each gauge have a different recievers?