My first Arisaka, Kokura Type 99

[dave]

For what its worth, keeping in mind books are never written in stone. "Until the 1930's parts were numbered with Assembly numbers of 1 to 3 digits. During the 1930's aresnals begin using last three digits of serial number to SOME parts, while others continued to be numbered to match a separate assembly number. After about 1940 the serial was used exclusively for matching numbered parts." Japanese Rifles of WW11" Duncan McCollum. A very basic beginners book, I know, so don't jump all over me!
My 99 Long is matched by serial, these were made in 1939.
38 Carbine # 42453, 5 series, is a m/m but has an assemb. #171 (barrel & rec.), bolt, safety, firing pin, floorplate are #453. Stock, handguard, dust cover are all numbered m/m.
Series 33 Toyo Kogya is matched by serial # but only bolt & rec. And it has many of early features which it 'should not', perhaps because of low # 5030.
Series 30 #41321 (1940-41) is matched by assemb. number 696 on rec., bolt & safety, bayo lug. No other numbers altho I did not take bolt apart.
44 Carbine # 57489. A m/m rifle but following have serials; bolt, renumber to 489, T.G, trigger, bolt release, some sight parts, fire pin, safty (match), upper lower tang.
Type 38 long 64241. Series 27. Rec. Assemb. #248. Safety, bayo lug, floorplate serial matched. two other small parts are m/m.
By the way, the so called 'series numbers' is a collectors term, never used by the Japanese. The numbers came about by the way the symbols are arranged in a Japanese poem (or something like that).