Bomb, 500 lb GP, AN-M43, AN-M64, AN-M64A1
These bombs are all general purpose high explosive bombs.
Bomb AN-M64A1 contains antiwithdrawal pins in the base plug and an adapter-booster and fuze adapter that can be locked in place. The earlier AN-M64 lacks these antiwithdrawal features.
Bomb AN-M64A1B1 is a 500 lb gas bomb AN-M78 with the following modifications: two MAU 76-A lugs are used in place of welded lugs used on bomb AN-M64A1: burster tube and bomb base are removed; and a portion of the bomb base of bomb AN-M64 is then welded to the bomb body. The closing plug used with the bomb base above has no provisions for base fuzing. Bomb AN-M64A1 has none of the above features. The explosive weights of bomb AN- M64A1B1 and bomb AN-M64A1 are identical.
The standard color scheme employed on these bombs since 11 March 1942 has been an olive drab body with yellow bands to indicate the HE filler. The banding system for Amatol and TNT fillers is a one-inch yellow band at the nose, a one-inch yellow band at the tail of the bomb body, and a 1/4-inch dotted band at the center of gravity.
The fuzing of these three bombs is the same, with these exceptions: The Tail Fuzes AN-Mk 230 and Mods and Mk 231 Mod 0 can be used in the GP Bomb, AN-M64 because this bomb has the Adapter Booster, M115 or M115A1. The Adapter Booster M115 has a sleeve that can be easily removed, making it possible to use a fuze with a larger diameter. With the removable sleeve screwed in the adapter booster, any Army tail fuze may be used. The GP Bomb, AN-M43 uses the Adapter Booster, M102, which has no removable sleeve and therefore cannot take the Hydrostatic Fuzes, AN-Mk 230 and Mk 231.
Approximately 50 percent of the complete weight of the bomb is an explosive filler of Amatol 50/50, TNT, Composition B, or Tritonal. Bombs filled with Amatol 50/50, such as that illustrated, include nose and tail surrounds of TNT, a body gasket, and an Auxiliary Booster M104. These features are not included with other explosives.
The AN-M64A1 contains one of the following fillers: Amatol 50/50 (257.2 lb, 116.9 kg), TNT (265.7 lb, 120.8 kg), Composition B (272.4 lb, 123.8 kg) or Tritonal (283 lb, 128.6 kg).
General Information, AN Series Bombs
Tail, Hydrostatic, AN-Mk 230 Mod 3 - 6
Tail, Hydrostatic, Mk 231 Mod 0
TM 9-1325-200, Bombs and Bomb Components (1966)
OP 2216, Volume 1 - Aircraft Bombs, Fuzes, and Associated Components (1960)
OP 1280, Aircraft Bombs (1955)
OP 1664, Volume 2 - US Explosive Ordnance (1947)
USNBD - Bombs and Fuzes, Pyrotechnics (1945)
TM 9-1904, Ammunition Inspection Guide (1944)