In late part of the 30's the Japanese undertook to develop a rifle for the 7.7x58 cartridge as they wanted a larger caliber rifle to be able to penetrate breastwork of the enemy.

Several rifles were offered and one of those was a modification of the T38 long rifle to accept the 7.7x58 cartridge. A new barrel with sights was installed on a T38 action, the magazine box was extended forward and the front feed ramp was shortened for the longer cartride. Also they inscribed on the top of the receiver Experimental 7.7 or Test Type 7.7. Added a recoil bolt to the stock and installed a wider recoil holder to fit the bolt and lug on bottom of receiver.

Last photo shows recoiled bolt and extra wide shoulder lug in both the carbine and the long rifle and a rectangular block inletted into the stock for the cleaning rod to screw into.