The Type 61 was a main battle tank developed and used by the Japan Ground Self-Defense Force, built by Mitsubishi Heavy Industries.(1961 to 1975) The maximum armour thickness is quoted as 64 millimeters. A 12.7 mm machine gun was normally mounted on the cuppola for anti-aircraft use. The main gun was the Type 61 90 millimeter caliber rifled gun with a horizontal sliding breach block. The gun is fitted with a t-shaped muzzle brake, which diverts firing gasses sideways, and reduces the amount of