FWIW, I know of no cock on opening "kit" for the Japanese rifles. There was one for the M1917 Enfield (which will also work on the Pattern 1914 and 1913)but not for the Arisakas. The Enfield kits work simply by changing the sear and cocking piece so the gun fires off the firing pin retraction cam. That means a very short firing pin movement and requires a stronger mainspring, which in turn makes bolt opening more difficult. (No free lunch, here, folks.)
Jim
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