Barrel info for discontinued Winchester Shotguns:
The 1200, 120, 1300, and Speed Feed model barrels will interchange. (Except for the extended magazine Defender series).
Just remember if a 3" chambered barrel is installed on a 2.75" 1200 don't expect the gun to feed or eject with the longer 3" rounds.
Conversely do not try to fire 3" shells in a 2.75" chambered 1200 barrel even if it is installed on a 1300.
Buyer beware
Critical point in selecting a used 1200, 120, 1300, Speed Feed, 1400, 1500 barrel:
The rotating bolt requires a long clearance slot for the extractor. If the barrel has seen a lot of use or is just slightly out of specification, the thin edge of the clearance slot may have a razor sharp worn edge that will cut shells in the feed cycle. Even worse, the extractor clearance slot may be worn thin and also exhibit small cracks, sometimes preventing shell feeding altogether.