Very nice find. Not common at all. Some came in as Korean War captures. Some in during the big import of 15 years ago. But not common. I had an NCO years back who I asked what they did with the Korean War battlefield rifles. He was an Ordnance NCO and knew his stuff. He said they picked up everything and buried it with TNT and then blew it all up. He said most was in poor shape and no one wanted the stuff. He did this for a living and was loikley correct.