http://i.imgur.com/fBqZOwO.jpg?1

http://i.imgur.com/h6nrtyn.jpg?1

I'm really not too familiar with WW2 history at all, but I know my grandpa fought the Japanese and I believe he was artillery. Anyways, this has become somewhat of an heirloom which my dad inherited and we've always been interested in it. There is a number engraved in the metal near the bolt (27993) if that helps. Also, I've asked a couple of people who spoke some Japanese if they could tell me what was written on the butt, however they've never been able to. If anyone was capable of translating it that would be awesome. If you need me to take some more pictures I'd be happy to. My grandpa died years before I was born and prior to retiring he was a Lt. Col in the Marines. My dad says he brought this gun back from the Pacific with him and I've always assumed it was a Japanese rifle that he brought back as some sort of trophy, but I'm not really sure. I've also got a shadowbox with his medals hanging up in the hallway downstairs that I could photograph if that could help with anything. Thanks in advance for any information you can provide, I love this sub.

Edit: More pictures of the rifle, check them out http://imgur.com/a/kHzim#0