The old joke is to saw it in half- and count the rings- but there is no one way to tell the age. It will depend on the make and model. In many cases, knowing the make and model and serial number, we can access published information. Some companies, such as Ruger and Browning, have it on their websites. Some guns, such as Remington, used a letter code to tell the date. In others, we can only tell the range of years that model was made. And with some guns, we can't tell at all, because we cannot confirm a maker.
how to tell the age of a 12 gauge single barrel shot gun made by American Gun Company?
By the serial number.
The model number of the gun and make along with the serial number usually will determine the age of a gun.
search up the gun name and how many mm it is
4092
To tell the age you need to:Provide the typeProvide all markings and decorations.Then an expert might be able to date it.
Possibly if it is a Browning made by Miroku.
You will have to tell us who made it and if it is a hand gun or long gun, caliber/gauge, etc..
Contact your local county sheriff's office during business hours. They can tell you.
Give us the make & model of the gun and maybe we can tell it's age.
If you call S&W, they will tell you when it left the factory.
The last patent date will tell you that it was made that date or later.