The Japanese Army made significant use of snipers (or in today’s terminology, designated marksmen) as part of its infantry combined arms doctrine, and produced about 22,000 Type 97 sniper rifles for use in WWII and the Sino-Japanese War. In 1941, shortly after the adoption of the new 7.7mm rifle cartridge, it was decided that a sniper rifle variant of the Type 99 should be made in addition to the Type 97 (which was basically a scoped Type 38).
Testing through 1941 determined that there was almost no practical difference in accuracy between scoped examples of the Type 99 long and short rifles, and so the short rifle was chosen to be the basis for the Type 99 sniper (the Type 99 long rifles would drop from production altogether pretty quickly anyway). About 1,000 of the scoped 99s were manufactured by the Kokura Arsenal using the same 2.5x scope as on the Type 97 sniper, while the Nagoya Arsenal instead used a 4x scope, offering more magnification at the expense of a narrower field of view. Nagoya would produce approximately 10,000 of these rifles, with 4x scopes except for a period between serial numbers 5,000 and 7,000 with 2.5x scopes (most likely the remainder stored at Kokura when that plant ceased production). The rifles made into snipers were given no special selection criteria; simply taken at random from normal production. The utility of the weapon in Japanese practice came not from it being mechanically more accurate than any other issue rifle, but rather from the optical sight allowing better exploitation of that standard rifle’s inherent accuracy.