armor. Armament The armament of the Montana-class battleships would have been similar to the preceding Iowa-class battleships, but with an increase in the number of primary guns and more potent secondary guns for use against enemy surface ships and aircraft. Had they been completed, the Montanas would have been gun-for-gun the most powerful battleships the United States had constructed, and the only US battleship class that would have rivaled the Imperial Japanese Navy battleships Yamato and Musashi in armament, armor, and displacement. Main battery The primary armament of a Montana-class battleship would have been twelve /50 caliber Mark 7 guns, which were to be housed in four three-gun turrets: two forward and two aft. The guns, the same used to arm the Iowa-class battleships, were long—50 times their bore, or 50 calibers, from breechface to muzzle. Each gun weighed about without the breech, or with the breech. They fired armor-piercing projectiles at a muzzle velocity of , or high-capacity projectiles at , with a range of up to . At maximum range, the projectile would have spent almost 1½ minutes in flight. The addition of the No. 4 turret would have allowed Montana to overtake Yamato as the battleship having the heaviest broadside overall; Montana and her sisters would have had a broadside of vs. for Yamato. Each turret would have rested within an armored barbette, but only the top of the barbette would have protruded above the main deck. The barbettes would have extended either four decks (turrets 1 and 4) or five decks (turrets 2 and 3) down. The lower spaces would have contained rooms for handling the projectiles and storing the powder bags used to fire them. Each turret would have required a crew of 94 men to operate. The turrets would not have been attached to the ship but would have rested on rollers; had any of the Montana-class ships capsized, the turrets would have fallen out. Each turret would have cost US$1.4 million, but this figure did not take into account the cost of the guns themselves. The turrets would have been "three-gun", not "triple", because each barrel would have elevated and fired independently. The ships could fire any combination of their guns, including a broadside of all twelve. Contrary to popular belief, the ships would not have noticeably moved sideways when a broadside was fired. The guns would have had an elevation range of