1) The exterior of the gun was sprayed with zinc for 25.5 in (64.8 cm) starting 20.25 in (31.4 cm) from the breech end.  The bore was chrome plated 0.0005 in (0.013 mm) deep for 246.0 in (6.248 m) from the muzzle.

2) During gunnery trials in March 1939, USS Savannah (CL-42) fired 138 rounds in one minute.

Reduced Charge - 21 lbs. (9.5 kg) SPDN
Reduced Flashless Charge - 22 lbs. (10.0 kg) SPDF

Reduced Charge - New Gun
   AP Mark 35 - 2,050 fps (625 mps)
   HC Mark 39 - 2,225 fps (678 mps)

1) The HC Mark 34 projectile body could be used with Point Detonating (PD), Mechanical Time (MT) or with proximity (VT) nose fuzes.  When used with PD fuzes, they were considered to be HC rounds while those with MT and VT fuzes were considered as AA rounds.  All versions used a base contact fuze.  A specially cavitized HC Mark 34 projectile was produced to be used with a VT fuze.  This projectile was unique in that it was the only VT fuzed projectile of the World War II period that used a base fuze.

2) The sources listed below differ as to barrel life.  I have chosen to use the figures given in "The Naval Institute Guide to World Naval Weapon Systems 1991/92."  A 105 lbs. (47.6 kg) HC round fired at 2,665 fps (812 mps) was equivalent to 0.71 ESR, the 130 lbs. (59.0 kg) Target round at 2,050 fps (625 mps) to 0.21 ESR and the 105 lbs. (47.6 kg) Target round at 2,300 fps (701 mps) was 0.21 ESR.

3) The cartridge cases were sealed with cork plugs which extended about 2.5 in (6.4 cm) past the mouth of the case.

4) Bourrelet diameter was 5.985 inches (15.2 cm).

5) Mark 4 was used for Full Charges while the Mark 4 Modified was used for Reduced Charges.

6) Some SPD cartridges had flashless pellets added which gave them a "reduced" flash.

Cleveland and Fargo classes:  165 to 173 tons (168 to 176 mt)

Cleveland and Fargo classes:  11 degrees per second

1) These mountings did not have the guns individually sleeved.  RPC was installed on all ships either as built or during refits.

2) Each gun was supplied by its own projectile and cartridge hoists which ran directly to the gunhouse.  The cartridge hoist was an endless conveyor type with open flights rather than powder cars.  Projectiles were delivered vertically to the side of the gun while cartridges were delivered to the rear of the gun.  Both were placed into the loading tray and then rammed together.  Cartridge cases were ejected through a port in the rear floor of the turret.  Shell stowage was on the fixed structure.

3) Each turret required a crew of 3 officers and 52 enlisted men.

4) These turrets were powered by electric motors with hydraulic drive gears.  Training motors were 50 HP while the elevation motors were 25 HP.  Each gun had a 7.5 HP motor which operated both the breech mechanism and the rammer, which was attached to the rear of the slide.  The three cartridge and three projectile hoists in each turret were driven by three 15 HP motors in the Brooklyn and St. Louis classes and by three 20 HP motors in the Cleveland and Fargo classes.

5) The Cleveland and Fargo classes had a slightly heavier and larger turret with more protection than the ones used for the Brooklyn and St. Louis classes.  Weight differences within a class were due primarily to the rangefinders, which were installed only on the first four turrets of the Brooklyn and St. Louis classes and only on the first three turrets of the Cleveland and Fargo classes.  Late during World War II some Cleveland class cruisers had the rangefinders removed from Turret I as a weight saving measure.

6) Compared to the Brooklyn and St. Louis classes, the Cleveland and Fargo classes traded one 6" (15.2 cm) turret for better fire control equipment and for a better secondary battery - eight 5"/25 (12.7 cm) guns (Brooklyn) or eight 5"/38 (12.7 cm) guns (St. Louis) vs. twelve 5"/38 (12.7 cm) guns (Cleveland and Fargo).  The Fargo class differed from the Cleveland class by having a single funnel and a more compact superstructure which gave their AA weapons better sky arcs.

7) Cleveland class cruisers converted into missile cruisers during the 1950s-60s had both stern turrets and three of their six 5"/38 (12.7 cm) twin mounts removed in order to fit a Terrier or Talos twin missile launcher in their place.  Those converted to flagships also had Turret II and two more 5"/38 (12.7 cm) twin mounts removed in order to fit additional staff accommodations.  Remaining turrets had the rangefinders removed.