If your firearm does have a serial number, if you will call or email to the address below, the serial number and model number we can determine the approximate age of your firearm. Contact Remington through their Help Center by e-mail at info@remington.com or call. Check the serial numbers located on the left side of the barrel on your Remington shotgun. Grafio for mac os x. They can be decoded to find out when your shotgun or rifle was manufactured. This serial number decoder will translate this information, determining the exact month and year that your specific firearms was created.