Remington uses a letter code on the left side of the barrel as the date code. Should be either two or three letters. The first is the month, the second and third are the year. This only helps if the original barrel is still on the rifle. The chart is on page 2036 of the 28th edition of the Blue Book. It says"Remington Date Code Data & SxS Shotgun Serialization" but it works on rifles also. If you don't have a Blue Book, post the letters here, or pm me and I can look it up for you.