They have date code stamps on the barrel which can be looked up on the manufacture date link on the Remington Society of America.
Don't know your exact question, but from 1940 to 1946 production of the Auto-5 was turned over to Remington. Serial number is on the side of receiver. "ABC" for American made Version. (A=16 gauge, B-12 gauge, C=20 gauge)
Your Browning superposed,over under 20 gauge shotgun was made in the year 1951;with the serial number that you have provided.
Not enough detail. Can you provide a serial number?
It comes in two gauges, 20.gauge and 12 gauge Was Russian gun, now gun rights bought and owned by Remington. Now sells under Remington as Remington Spartan. Still sold under Baikal name.
You must provide the serial number for the question to be answered.
It is found under the breach below the barrel
On the breach under the barel
It won't have one. There may be some numbers under the barrel on the forearm, but they will not be serial numbers.
Since 1921 Remington has date stamped the barrel you can find the details/table on the Remington Society of America under the Manufactured Date link.
Browning.com has a sn function under customer service.
Most likely a Superposed.
Browning.com has a sn function under customer service.