Rifles produced early, when Japan controlled much of the Pacific theater, had many accessories lacking on later models. Over the course of the war, the manufacture of the Type 99 changed considerably. 303 British for use in copied Vickers machine guns, and will not chamber in a Type 99. Unrelated to 7.7 Arisaka, the Japanese also produced many rimmed 7.7 cartridges. The new ammunition was the equal of its western counterparts, with the same caliber as the. For the Type 99, they introduced the 7.7x58mm round, also known as 7.7 Arisaka or 7.7 Japanese. When the Type 99 was designed, the Japanese military was disappointed in the performance of the 6.5x50 mm cartridge used in the Type 38. Rifles for police use or training may have different markings. All Type 99s manufactured for military use are identified by kanji for "Type 99" stamped into the receiver, along with a 16-petal chrysanthemum. It utilizes a simple bolt action heavily based on the Mauser design, but stronger. The Type 99 was produced between 19 by a variety of arsenals in Japan, several abroad, and by many civilian manufacturers such as Toyo Kogyo. Although it was intended to replace the older, less powerful Type 38, the complications of war led to both rifles seeing widespread use. The Arisaka Type 99 was the primary infantry weapon of the Imperial Japanese Army during World War II.