Thanks eldeguello,

It was the earlier Arisakas in 6.5mm. I thought P.O. Ackley conducted these tests while working at the Springfield Armory as part of military testing? (Or where they done later in his career?) I know the 7.7 Japanese was adopted in 1939 in the Model 99 Arisaka, though both it and the 6.5 Japanese continuted to see use throughout the war. What I am definitely not certain about...is how the two models differed. Though I was aware that the late war models were horrible in their " lack of quality control" . (Similar circumstances happened with late war model Mausers...though not as significantly.)

P.S. Can you recommend a good definitive source, (preferably on the internet)? Once I get back to AK, and settled, I' m looking forward to catching up on some reading.

Thanks again!