While cleaning out my Mom's attic I came across a Remington Nylon 12 bolt action .22. My Dad was a Game Warden for all his life so I have no idea where this gun came from. He also handled a lot of State guns and had a Class 1 FFL. I tried to find the serial number on this gun and there is not one to be found. It should be on the receiver I think. The only numbers I have found are on the barrel AJ 58 (I am not sure of the 5) and a D near the Remington logo. Inside the stock there are numbers stenciled inside 3 3070 also not sure of the 3's they could be 8's. The gun is in beautiful shape,any help on this gun would be appreciated. When did Remington start putting serial #'s on their guns. Could someone tell me what these numbers I found one this gun mean?