8"/35 caliber gun

The 8"/35 caliber gun (spoken "eight-inch-thirty-five--caliber") were used for the primary batteries of the United States Navy's first armored cruisers and the secondary batteries for their first battleships.

Mark 3
The Mark 3 Experimental was a 30 caliber gun that used trunnions and had 11 hoops with the outer hoop starting 4 in from the breech and running out to the muzzle. The production Mark 3 Mod 0 was a trunnioned 35 caliber gun that had 11 hoops with the outer hoop starting 4 in from the breech and running out to 43.5 in from the muzzle. This gun was removed from service prior to World War I. The Mark 3 Mod 1 was constructed of tube, jacket and eight hoops while Mod 2 was identical to Mod 1 but with different steps under the chase hoops. Mod 3 was for one gun lengthened to 40 calibers and was removed from service prior to the start of World War I. Mod 4 was for one gun with minor changes from Mod 3. Mod 5 had the trunnions removed and the outer jacket threaded to accept a sleeve.

Mark 4
The original Mark 4 guns were identical to Mark 3 Mod 1 guns with the trunnion hoop and elevating band removed and with the threads formerly under the trunnion hoop being continued to the rear of the gun. This allowed these guns to be screwed into the sleeve of a two-gun turret mount. Mark 4 Mod 1 was one Mark 4 gun shortened by 0.66 in in rear of the threads. Mods 2 through 9 were for minor differences primarily for testing different mounting techniques. Mod 10 was for one gun cut down to 23 calibers and used for experimental work with high-explosive shells.

Mark 5
Mark 5 was a new 40 caliber design intended for armored cruisers and battleship secondaries and constructed of tube, jacket, three hoops and one locking ring. This gun had a muzzle bell. Unfortunately, the Mark 5 proved to be unable to handle the transition from black powder to nitrocellulose propellants as the new propellant burned more slowly, which allowed pressure to build up to unsafe levels as the projectile traveled down the bore. This problem was illustrated when USS Colorado (ACR-7) blew off the muzzle of one of her 8"/40 (20.3 cm) guns during gunnery practice off Chefoo, Shantung, on 22 June 1907. All Mark 5 guns were subsequently removed from service, lengthened to 45 calibers by adding a new liner and rehooped to the muzzle, redesignated as Mod 1 and then placed into reserve. Two of these Mod 1 guns were given a slightly different breech mechanism and gas seat and then designated as Mod 2. were subsequently rearmed with the stronger 8 in/45 Mark 6 guns.