Mark 19 Mod 2 (one-piece):  3,560 lbs. (1,615 kg)

1) This weapon has many different kinds of ammunition.  The ones listed above are meant to be representational, but by no means is this a complete listing.

2) Ammunition abbreviations:
   HE-PD = High Explosive, Point Detonating Fuze
   HE-VT = High Explosive, Variable Time Fuze
   HE-CVT = High Explosive, Controlled Variable Time Fuze
   HE-IR = High Explosive, Infrared Fuze
   Illum - MT = Illumination, Mechanical Time Fuze
   MT-PD = Mechanical Time, Point Detonating Fuze

3) All projectiles have a 0.5 caliber boat-tail.

4) The illumination round burns for approximately 50 seconds.

5) The Arleigh Burke class ammunition magazine takes approximately 16 hours to be loaded out with 680 ballistic projectiles and associated propelling charges during at-sea replenishments.  This assumes favorable weather conditions and calm seas.  The Ticonderoga class requires 12 to 16 hours for each 600 round magazine, assuming that sufficient manpower and replenishment assets are available to simultaneously resupply both forward and aft magazines.

6) This weapon is capable of using the BTERM II rounds made by Alliant Techsystems.  See 5"/62 (12.7 cm) Mod 4 data page for additional information.

7) Most conventional rounds have a warhead of about 7.75 lbs. (3.515 kg).

8) The gun feeds from a single loader drum holding 20 projectiles and cartridges.  The fuze setter is located directly above the transfer station, which feeds rounds from the drum into the upper hoist.

Tarawa (2), California (2), Virginia (2), Ticonderoga (2), Arleigh Burke (1), Spruance (2) and Kidd (2) classes:  Mark 45

1) Since the maximum elevation of this mounting is limited to 65 degrees, there is no need for a complex cradle system to move ammunition around the gun and then throw it into a loading tray from above.  Instead, the gun is fed from below by a cradle swinging out and up from a fixed ammunition hoist in the center of rotation of the mount.  Rounds are rammed directly from the cradle, which follows the rotation of the mount.  As mentioned, the ammunition hoist is fixed in rotation and feeds from a single drum loader.  The result of this design is a very light mounting at the cost of a lower rate of fire and a lower maximum elevation.  Mean Time Between Failures (MTBF) is 100 hours.

2) This mounting consists of two groups, the upper and lower.  The lower structure (below deck) delivers an uninterrupted flow of ammunition and contains the mount control unit, loader drum, fuze setter, hoist and lower accumulator system.  The upper structure consists of the gun house shield, upper accumulator system  and mechanisms to load the gun, lay the gun, fire the gun and handle the spent cartridge.

3) The recoil distances given above are nominal values when firing a standard service charge at elevations between 30 and 40 degrees.  When fired with a proof charge at max elevation, recoil is about 23 inches (58 cm).  The absolute, metal-to-metal recoil distance is 24 inches (61 cm).

4) The Mark 45 manning includes one gun captain, one panel operator and four ammunition loaders, all located below the gun deck.

5) The Mark 45 has a bore time of 0.02 seconds and has recoiled about 2 inches (5 cm) when the projectile leaves the muzzle.