In this article I will show you the Japanese M1 M13 M27 links.
All of them are stamped with the markings of “AO” or “AO” and the type of link.
The M1 has only the “AO” stamp. It also has white paint on it for every 50 rounds.
The M13 is stamped with “AO” and “M13”.
The stamps on the M13 and M27 are thin and a little hard to read.
The M27 is similar to the M13 in that it is stamped with “AO” and “M27”.