Mike, The serial number should be engraved on the trigger guard. If you don't find it there, or can't read it, it will be on the water table of the receiver. Before you remove the forend and the barrels to read the number on the receiver, make sure to cock the action. Don't pull the triggers once you have separated the forend and barrels. The action must be cocked before assembly. If you accidently uncock the action while the pieces are separated, you should recock it with a special tool or carefully with pliers or a screw driver, prior to reassembly