The Imperial Japanese Army (IJA) developed the Type 99 based on the Type 38 rifle but with a caliber of 7.7mm. The Type 99 was produced at nine different arsenals. Seven arsenals were located in Japan, with the other two located at Mukden in China and Jinsen in Korea.
The IJA had intended to completely replace the Type 38 with the Type 99 by the end of the war. However, the outbreak of the Pacific war never allowed the army to completely replace the Type 38 and so the IJA used both rifles during the war. As the war progressed, more and more cost saving steps were introduced in order to speed up production. Late war rifles are often called "Last Ditch" or "Substitute Standard" due to their crudeness of finish. They are generally as crude as the 1945 dated Mauser K98k of Germany.
The Type 99 was produced in four versions, the regular issue Type 99 Short Rifle, the Type 99 Long Rifle (a limited production variant) and takedown Type 2 Paratroop Rifle and the Sniper Rifle Type 99. The standard rifle also came with a wire monopod and an anti-aircraft sighting device. The Type 99 was the first mass produced infantry rifle to have a chrome lined bore to ease cleaning. All of these features were abandoned by mid-war.