PUBLISHERS OF FINE BOOKS FOR THE GUN COLLECTOR Does this rear sight belong on a. 4570 Springfield Trapdoor carbine with this serial number Answer No, it. The production of the 22 SemiAuto rifle began in 1914, and was officially imported by Browning in 1956. It is still in production today. To find your serial number. Semi Auto Rifle. In 1. 97. 4, production of the 2. Semi Auto was moved to Miroku, Japan. The order of the serial number code was changed to 1. Serial Number which started at 1. Two digit year code. Rifle type code TLong Rifle Caliber. EShort Rifle Caliber. NOTE FOR MANY MIROKU GUNS FROM 1. AND PART OF 7. 6, THE YEAR WAS REVERSED IN THE SERIAL NUMBER. WOULD MEAN 1. 97. Example 1. 00. 0T4. A 1. 97. 4 2. 2 Semi Auto rifle in 2. Long Rifle Caliber with a serial number of 1.