American Projectiles and Explosives
Practice Bombs
Army Practice Bombs
3-pound AN-Mk 5 Mod 1
See Navy Practice Bombs
20-pound M48
This is a dummy of the 20-pound Fragmentation Bomb AN-M41. It has a two-ounce black-powder charge and uses the Fuze M110 or AN-M110A1 in the nose. It is 21.8-inches long; weighs 19.7 pounds. It is issued in practice bomb clusters M2 and M2A1.
23-pound M71 and M71A1
These are parachute-type practice fragmentation bombs for clustering. They do not have a fuze or spotting charge, because of the presence of the parachute. The parachute assembly is the M3, modified from the M4 by removal of the suspension assembly, hand assembly, and pull wire container. M71 is 26.9 inches long; weighs 21 pounds. M71A1 differs by the addition of the shoulder to the bomb nose.
100-pound M38A2
Overall length: 47.5 inches
Diameter: 8.13 inches
Weight (empty): 15.7 pounds
Weight (sand-loaded and spotting charge): 100 pounds
This bomb simulates a G.P. bomb of the same size. The spotting charge is assembled in a sleeve at the base of the bomb, within the fin box. Authorized spotting charges are M1A1, M3, and M4.
100-pound M75
Diameter: 8 inches
Filler (hematite): 72 pounds
Total Weight: 101.3 pounds
This bomb is designed to provide a target reference for practice bombing over snow-covered ranges. Resembling the chemical bomb of the same size, it consists of a light, sheet-metal case; a charge of red iron ore (hematite); a Burster M4; and a Fuze M108 in the nose.
100-pound M85
This model is a reinforced concrete design ordered to relieve a temporary shortage of the Practice Bomb M38A2 during the war.
Spotting Charge (Army)
M1A1
Overall length: 11.18 inches
Diameter: 3.43 inches
Weight: 4.25 pounds
Black-powder charge: 3 pounds
Bomb used in: M38A2
This type of spotting charge fits in the after end of the 100-pound Practice Bomb M38A2. It produces a flash of flame and white smoke for observation of bombing accuracy. When assembled in the bomb, the can of the charge protrudes two to three inches out of the bomb body.
The fuze is an integral part of the spotting charge assembly. When the arming wire is pulled, the spring-loaded arming pin jumps out, leaving the inertia weight supported only by the combination firing pin and creep spring. On impact, the inertia weight drives this firing pin into the shotgun-type primer, which, in turn, ignites the black powder.
M3: The Spotting charge M3 has a 2 and 1/3-pound dark smoke filling and a black-powder igniter. It is 5/8 inches longer than the Spotting Charge M1A1, but otherwise is like it. The M3, with its dark smoke filler, is well adapted for bombing practice over snow-covered terrain. The black-powder igniter charge contains approximately 425 grains. It is used in the Practice Bomb M38A2.
M5
Overall length: 7.37 inches
Diameter: 2.95 inches
Material: Glass
FS filler: 14.4 fluid ounces
The Spotting Charge M5 consists of a glass bottle filled with FS smoke mixture. An ordinary bottle cap seals the mixture. The bottle is held to the Practice Bomb M38A2 by a wire twisted around the neck of the bottle and attached to the tail vanes. The charge assembly weighs 2.54 pounds.
Diameter: 2.95 inches
Material: Glass
FS filler: 14.4 fluid ounces
The Spotting Charge M5 consists of a glass bottle filled with FS smoke mixture. An ordinary bottle cap seals the mixture. The bottle is held to the Practice Bomb M38A2 by a wire twisted around the neck of the bottle and attached to the tail vanes. The charge assembly weighs 2.54 pounds.