It was the Italians who made rifles for Japan. They used the Carcno action and the magazine and floor plate form the Arisaka but did not use wrist tangs. Some say 60K were made and shipped to Japan and some accounts say l120K. They are called Type I rifles. They do not have the oversize chamber of the T38's.
riceone-
At least some Type I rifles had the oversize chambers.
One of the better researched and documented articles ever published in
Handloader was James Taylor's "A Case for the 6.5 Arisaka", from Number 111 in 1984. Taylor found his sample Type I had the same oversize chamber as the Type 38s he measured. My own Type I has the oversize chamber.
(It is perhaps better to say that 6.5x50 cases of modern and WWII manufacture are undersized, rather than that the chambers are oversized. Earlier Arisaka cases have a case head diameter of .455, according to Barnes'
Cartridges of the World. These would fit the chambers well. My Norma cases have head diameters that measure .447, and show some bulging when fired in the Arisaka rifles I've handled.)
--Bob
