Japanese rifling types

[vintage hunter]

I have 1 Kokura Series 23 T38 rifle, 1 Koishikawa no series T38 carbine with 6 lands/ grooves made around 1910 , 2 Nagoya series 4 carbines, 1 Kokura series 20? T99 short rifle and 1 Nagoya no series T99 long rifle s/n 78xx and they all have Metford derived rifling.

[WarPig1976]

1 Kokura series 20? T99 short rifle
Same here, I think we used the same site to ID markings. It doesn't exactly match but its the closest. Metford here also.....