Actually I read about a study the US did after the war where they wanted to determine the characteristics of different firearms used during the was. Amazingly enough the Japaneses Arisake came out on top in many way as it was found that the action of this firearm was able to withstand much higher pressures than was found using the recommended ammo. Not sure if this would apply to late war firearms or not as I don't know what changes were made to production late in the war.
Bookmarks