Hello WHG,

The first thing you'll need to know is almost all production records for Japanese Weapons were lost/destroyed at the end of the war.
The dating of early 6.5 weapons is somewhat difficult, but very close estimates have been compiled over a 50 year period by the "Banzai" Japanese collectors group, of which I am a 35+ year member. This information has been put together in a book, "The Type 38 Arisaka", Banzai Special Project #8, written by Francis (Frank) Allan and the late Harold Macy.

The early research in the mid 1970's by Fred Honeycutt and the late Harry Derby was instrumental, because they both were able to talk to several of the surviving Japanese Arsenal superintendents, which oversaw the production at these Arsenals and had their notes from that time period. Even though they were not able to give exact production figures, they had very close approximations of how many rifles and pistols were made each month.

One of the ways that has been very helpful in dating the early 6.5mm family of rifles is looking at and comparing the proof marks of the early Nambu pistols (Papa and Baby's), as well as the early T-14's produced at the Tokyo Army Arsenal and Chigusa Factory of the Nagoya Army Arsenal, which were dated on the receiver starting in 1925.

Your rifle is a Tokyo (Koishikawa) product, probably manufactured in 1918. It is a 1st bayonet variation. I will (Hopefully) attach a flyer will give you instruction to obtain the book mentioned above directly from the writer. Hope this has been helpful!
Adver SCAN Revised T38 book order form.jpg