The Type 99 came into active service in 1939, and was used alongside the older Type 11 and Type 96, as these models had been produced in large quantities and many front line troops continued to use the Type 38 rifles with their 6.5 mm ammunition. All three weapons remained in service until the end of the war. The Type 99 was used by Communist forces (Chinese and North Korean armies) during the Korean War. It was used by the Viet Minh and the North Vietnamese forces during the First and Second Indochina Wars.