 These rifles were built on Danish Nielsen & Winther machinery originally for the Manchurian warlord Chang Tso Lin beginning in 1924.When Japan took over the arsenal after the Manchurian Incident of 1931, the Type 13 rifle continued to be produced in 7.92×57mm Mauser caliber, however an unknown number were also produced in 6.5×50mm.The Type I rifles built by Italy for Japan under the terms of the Anti-Comintern pact from 1939 to 1943 are in standard 6.5×50mm Jap.