The Japanese Type 38 (as in the 38th year of the Meiji period) rifle, was first adopted in 1906 by the Emperor’s troops after feedback from the recent wars with Qing-dynasty China and Imperial Russia. Almost 3 million of these simple bolt-action 6.5x50mm rifles would be made at three Japanese arsenals (Tokyo, Kokura, Nagoya) as well as one in Japanese-occupied Korea (Jinsen) and Manchuria (Mukden) until as late as 1944. While you would think that these all went into Japanese military hands, you would be incorrect as lots were exported abroad including 728,000 to Russia of all places during the Great War; 150,000 to the UK to arm British sailors in the same conflict; 200,000 to Republican China in 1917-18; 24,000 to Estonia in the 1920s.
One of the lesser-known Arisaka rifle contracts was from the government of Siam, now Thailand, which had ordered several aircraft, naval vessels, and small arms from the increasingly powerful Asian power in the 1930s. The Thais bought 50,000 “Type 66” (Type 38s chambered in Bangkok’s domestic 8x52R caliber) in 1924 from the Tokyo Army Arsenal. These were later augmented by a smaller quantity of 6.5×50-chambered guns provided as military aid in WWII. Post-war, some of each were converted to 30.06 M2, of which the government had a lot of due to close relations with the U.S., and dubbed Type 83/88s. They even carried them to war in Korea in the 1950s.
It would seem that at least some of those (probably non-firing) Arisakas are still soldiering on in Thailand as training rifles, as witnessed by these recent photos:
The above green-uniformed/bereted troops are members of the NST, or Military Student Training Supervisory Authority. The program, which runs for five years, is coordinated by local Territorial Defense Commands in the country and trains young men and women 17-25 with some 40-to-80 hours of field/classwork per year instead of joining the military proper for a period of active service (Thailand has conscription). After completion of the NST period, members transition to a non-drilling reserve.
Besides the Arisakas, the NST also uses lots of M1 Carbines, M1 Garands, and M60 GPMGs in their live-fire and fieldwork, which is run by local cadres from active-duty units. Besides the Vietnam-era hardware, they also run locally-made ALICE gear, M1956 style bottle canteens, and the like.