hi vern
good morning to you thanks for weighing in here both my self and dave needed an expert like you to help us out here if any one knew it would be you your thoughts and mine are the same but any way like we said before never say never could be might be some naval marked even going back 1970s midway produced japanese 8mm ammo to the exact specs plus no head stamps at all if you put the original 8mm round next to the midway cant see any difference at all alsi in the 1965 i bought my first japanese officers type 14 pistol no ammo to fire it i looked in the shotgun news and found a ww2 navy man makeing 8mm nambu on a 38call short shell necked down to acept the bottle neck cartridge but he said to me the shells may expand and split but no harm will come to me and i fired all the rounds and some split but no problems came to me 50 rds for i believe 22.00 shipped it was fun fireing this japanese officers pistol vern its my pleasure to have you abord with me and dave god bless all andy militarynut