Type 64

The Japanese Defense Agency initiated development of a domestic battle rifle to replace the M1 Garand rifles previously supplied by the United States. Howa developed several prototype designs during this research process. The initial R1 and R2 prototypes derived their layout from the Armalite AR-10, while the R3 prototype incorporated features of the M14, including a curved magazine. Subsequent feedback led to the R63E prototype, which served as the direct basis for the final weapon. Designed by Kenzo Iwashita and Giichi Dōgane, the rifle was manufactured by Howa. Production began in 1964 and concluded in 1988, with Howa securing the trademark rights in 1966.

The firearm utilizes a gas-operated short-stroke piston system with a tilting bolt and a linear hammer, a design inspired by the FN FAL and SVT-40. It features an external gas regulator to manage the cyclic rate and a rate of fire reducer, along with a setting to cut off gas to the piston for launching rifle grenades. The bolt remains open after the final round is fired, though removing the magazine causes the bolt to slam forward. To reduce recoil and muzzle climb, the weapon was designed around ammunition with a reduced propellant charge, though the gas regulator can be adjusted for standard ammunition at the cost of accelerated component wear. The physical design includes a stock equipped with a hinged buttplate and folding iron sights consisting of a flip-up rear aperture and a winged front post. The selector switch is marked with the Japanese characters for safe, semi-automatic, and fully automatic, spelling the word meaning "hit the target."

The weapon entered service with the Japan Self-Defense Forces in 1964 and was also adopted by the Japan Coast Guard and police Special Assault Team. Due to national export restrictions, the rifle was never exported. Although the Howa Type 89 began replacing it as the primary service rifle between 1989 and 1990, the weapon remains in active service across all branches of the Self-Defense Forces and the Coast Guard. For designated marksmen, a variant equipped with an optical scope was fielded, featuring optics produced by Nikon or surplus military scopes. This marksman configuration utilizes a single-screw mounting system and was eventually phased out of front-line army units in favor of the M24 Sniper Weapon System starting in 2002.