Gas operated
Your Winchester model 1400 semi auto shotgun is gas operated.
The Auto-5 Light 20 has no gas system. It is a recoil operated shotgun. Make sure the gun is cleaned properly and that the outside of the magazine tube is not oiled. Have the gun checked over by a gunsmith and he can show you the proper way to install the recoil system components.
If you are talking about a auto-5 shotgun? Then your auto-5 magnum shotgun was made in 1959.
Being that you said auto shotgun,then you have the Browning auto-5 shotgun that was made by FN in Belgium from 1903-1975.Your serial number indicates that your Shotgun was made in the year 1938.
The Auto Assault-12 shotgun is the AA-12 the most powerful action close combat shotgun in the World. The Auto Assault-12 is really the machine shotgun, not like a regular shotgun. The AA-12 is the only powerful shotgun that can pears through wall, body armor with the grenade and even vehicles.
Odd question... It's a auto-loading shotgun made from 1905-1947, actually it is the FIRST auto-loading shotgun produced in the U.S.A. !
Your western auto model 312AA shotgun was made by mossberg for western auto.The mossberg model 395,395K are the mossberg model designations for your shotgun.
If your browning auto-5 shotgun is a 12gauge,then it was made in 1927.If you have a 16 gauge shotgun then it was made in 1934.
Depending on condition,your browning auto-5 shotgun is valued at between 425-725 dollars.
your browning model auto-5 shotgun is valued at between 375-650 dollars.
Your browning auto-5 shotgun was made by FN of belguim for browning in 1957.