what were the typical armaments found in such a class?
An increase in the number of primary guns and more potent secondary guns for use against enemy surface ships and aircraft.
Montana-class battleship
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. 
what is montana-class battleship? A class of battleships can you specifically name a few battleships that come under that class? USS "Ohio", USS "Maine", USS "New Hampshire" which company built this class? The United States Navy which wars did such class of warships participated in? World War II
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Montana-class battleship [SEP] 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 "Montana"s 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.