Its a Type 38 6.5x53 Japanese long rifle. They also made carbine versions.
The two gas vent holes on the receiver ring say T-38. If it were one vent hole, it would be a 7.7x58 Type 99.
Clean it carefully, but lightly. See if the screws are still staked before you start to turn them, they are often staked and desirable when found that way. Hopefully the woods original Urushi finish is under al that dirt and dust.
Thanks for the ID! My Japanese rifle ID is a bit shaky. Just a clarification, the caliber of the T38 is 6.5x50. Sure you knew this, and just mis-typed.
I presently own one of those "stacked bodies" T-38s that
@5whiskey was talking about. I'll tell you the full story as I know it, since Arisaka threads don't come up often and it may be enjoyable for some.
A close friend's Grandfather sent the rifle back from the Pacific theater. I'll see how well I can remember as it's been over 20 years since the old man told me the story himself. It's a T38 carbine he captured from a coastal artillery position on an Atoll I've forgotten the name of. It was part of the larger Guadalcanal operation. His Reising was disabled in the action, and he actually fielded a carbine for awhile until he was able to replace it with a Springfield, and later that with a Thompson. His quip while telling the story was he only used guns with blood on them (insert sardonic laugh). He showed me the USMC medal he was awarded in taking that position. He also said that he didn't believe he killed the actual soldier carrying the rifle he sent home, (found one in better condition to put on the boat home), but that he did field the exact rifle after taking it from one guarding the approach to the big gun with his "H&R single shot". Said it was like a bolt action version of his dad's .25-35 deer rifle, and quite nice to shoot in combat...handy in tight places and quick to the shoulder. He was a man of light build, so he got sent into a lot of tight spaces. After taking the T38 and the man wielding it, he crawled through a crack in the rocks to a high position, and reduced the gun crew and support with (T38) rifle fire, taking the gun out of action and paving the road for the final assault of the position. Soapy was a young woodsman before entering service, and an old woodsman in the brief time I knew him. Said the only reason he sent it home is he thought it would make a handy deer rifle in the Northern MN forests. He killed many deer and bears and even a moose with it after returning home, all with field expedient soft points made from surplus military ball.
My friend is not much of a gun guy. A few years after Grandpa's passing, I asked him about the old rifle. We did some digging in the attic and there it was. Luckily 2 feet away from the leak in the roof! It was dusty but not rusty. Unfortunately gramp's box of "war stuff" including medals, papers, uniforms, bayonets and other stuff was directly under the leak and had morphed into an amorphous green blob. Wanting a home defense handgun, my friend traded me the rifle for a knock off Beretta 92 on the condition I never sell the Arisaka and if possible let him shoot it occasionally when I visit. Yep, no problem!