How can you found out your serial number for your gun?

Answer 1

== == Stamped serial numbers cause deformation of the metal deep below the surface and can be read even when filed off.

Something that coin collectors use to recover worn off markings on coins is a chemical called Nicodate that could be used on nickles. It might be worth a try. A forensic expert might use acid etching or various scans to recover the number, but that kind of service will likely be expensive.

Answer 2

Look carefully all around the gun. If it has a serial number, the number will be stamped somewhere where you can see it. If you can't find the number, that may mean that there isn't one. Early guns often did not have a serial number assigned to them and this practice went on until 1968 in some cases.