Its single 90mm main gun (the manual erroneously states that it is a 105mm gun) allows the Medium tank to be a match for enemy armour without sacrificing maneuverability. Due to its good speed, decent firepower, average rate of fire and tough armour the Medium tank became an incredibly successful tank. Their deployment, which helped to alleviate the Allies' marked inferiority in armor, allegedly angered Stalin to the point where he rushed the Mammoth tank into production, culminating in that unit's somewhat imperfect self repair capabilities.