4"/40 caliber gun

The 4"/40 caliber gun (spoken "four-inch-forty-caliber") was used for the secondary batteries on the United States Navy's battleship Iowa, Columbia-class protected cruisers, and the armored cruiser New York, and was the primary batteries on the gunboats Nashville, Wilmington, and Helena.

4"/40 caliber gun

The 4"/40 caliber gun (spoken "four-inch-forty-caliber") was used for the secondary batteries on the United States Navy's battleship Iowa, Columbia-class protected cruisers, and the armored cruiser New York, and was the primary batteries on the gunboats Nashville, Wilmington, and Helena.