I have a A5 20ga. My father purchased it in the early 1960's. I'm having trouble dating the gun. The serial number starts with 1Z. The Browning web site states that serial numbers should have a M or G. My dad referred to it as a Lighting 20. At 51/2 lbs it is light. It only chambers 2 3/4" shells.

I found a barrel but it has a vent rib. Mine has a round barrel that is etched down the top. Will this barrel work? The barrel is chambered for 2 3/4" also. I know the chamber must match the receiver.