American Projectiles and Explosives
Minor Caliber Projectiles
20mm Ammunition
Two types of 20mm weapons are at present in service use in the Navy: the Oerlikon anti-aircraft gun and the Hispano-Suiza aircraft gun. These types differ widely in construction and functioning; and it is emphasized that the ammunition, though somewhat similar in external appearance, is not interchangeable.
Ammunition for Oerlikon Gun
The Oerlikon gun and its ammunition are of naval manufacture and design. The ammunition may be distinguished from that designed for the Hispano-Suize gun by the reduced diameter of the extractor lip at the base of the cartridge case. For identification of the individual types of rounds, the body of the projectile is painted a distinctive color, as follows:
*When the projectile is assembled with "Dark Ignition" tracers, a 1/8-inch bright red band will be painted around it midway between the bourrelet and the rotating band.
The Mark and Mod, manufacturer's initials or symbol, and lot number are stamped around the body of the projectile.
Abbreviations in Minor Calibers
H.E. --- High Explosive
I. --- Incendiary
T. --- Tracer
B.L. --- Blind Loaded
P. --- Plugged
S.D. --- Self-Destructive
D.I. --- Dark Ignition
Ammunition for Hispano-Suiza Gun
This gun and its ammunition are Army-designed but have been adopted as Naval equipment with the installation of the gun on Naval planes. The ammunition is distinguished from that designed for the Oerlikon gun by the extractor lip on the base of the cartridge, which is the same diameter as the rest of the case. Two series of ammunition for this gun are in use. The "Old Series" consists of unmatched rounds, some adapter from British prototype, others designed by the Army. The "New Series" is a set of ballistically matched rounds designed by the Army to supersede those of the "Old Series". For identification of the individual types of rounds, the body of the projectile is painted a distinctive color, as follows:
1.1"/75 Ammunition
The body of these projectiles, now obsolete items, were unpainted except for two dots below the fuze, indicating as follows:
Explosive D --- Yellow dot
Tracer --- Red dot
A newer color marking was proposed for the 1.1-inch ammunition. Some projectiles may be found painted as follows:
H.E.-T. -- Light Gray with White band
H.E.-T./S.D. -- Dark Green with White band
B.L. and P. -- Red overall
B.L. and T. -- Red overall with White band
40mm Ammunition
These projectiles are identified by distinctively colored bodies, as follows:
The tracer composition is either a red burning mixture in the tracer -- "T" rounds -- or a non-luminous burning compound in the "Self-Destructive" rounds.
"Dark" and "Dark Ignition Tracer": To eliminate the blinding effect on 40mm and 20mm gunners from tracer fire at night, and also to make the origin of tracer fire less distinct, these tracers were developed toward the close of the war. The dark ignition tracer is invisible until the projectile is 100 to 400 yards from the gun's muzzle, and then it is visible for the rest of its time of flight. Details of these tracers are described with their appropriate projectile and tracer housing.
Inert Fillers
(For details on explosive payloads, please see earlier updates in the US explosive updates)
Blind Loaded and Plugged (B.L. & P.): A projectile may be loaded with sand or other inert material and sealed with a solid base plug, or the tracer hole (fuze hole) in a base plug may be blanked off.
Blind Loaded and Tracer (B.L. & T.): These projectiles have an inert load, but a tracer is inserted in the fuze hole of the base plug.
White Phosphorus: An unstable smoke-incendiary agent, white phosphorus ignites when exposed to air and produces dense white smoke. It also has its incendiary, anti-personnel effect.
Gas: The various types of gas fillings are listed further below.
Color and Markings of new projectiles, 3-inch and larger
Explosive Indicator
Yellow ---- Explosive D
Grey ---- Black Powder
Green ---- TNT
1/2 Grey and 1/2 Green band ---- TNT and Black Powder mix
Red ---- Inert material or empty
Blue ---- Composition A
Chemical Filler Markings
Two green bands, 1/2-inch apart ---- Persistent casualty gas
One green band ---- Non-persistent casualty gas
One red band ---- Harassing gas
One yellow band ---- Smoke
One purple band ---- Incendiary
Also, on projectiles having a chemical filler, there is stenciled the type of chemical, such as SMOKE, INCENDIARY, or GAS, and the symbol or letter designating the particular filler.
Color and Marking of older projectiles, 3-inch and larger
In addition to the explosive filler, body color, spotting specifications, and base and band stamping mentioned above, the older projectiles had the following markings:
Tracer Band: White band with three dots, indicating tracer color, 120 degrees apart.
V.T. Fuzing: One-half inch red band painted one-half inch abaft the nose fuze.
Stenciled on the body
-Size, caliber, Mark and Mod of projectile
-Mark and Mod of fuzes
-Explosive filling and density of loading
-Abbreviated name of loading dept.
-Initials of Chief Inspector
-Date of filling and marking; any changes in filling, fuzing, etc.
Stamped on base
Weights before and after filling.
20mm Ammunition
Two types of 20mm weapons are at present in service use in the Navy: the Oerlikon anti-aircraft gun and the Hispano-Suiza aircraft gun. These types differ widely in construction and functioning; and it is emphasized that the ammunition, though somewhat similar in external appearance, is not interchangeable.
Ammunition for Oerlikon Gun
The Oerlikon gun and its ammunition are of naval manufacture and design. The ammunition may be distinguished from that designed for the Hispano-Suize gun by the reduced diameter of the extractor lip at the base of the cartridge case. For identification of the individual types of rounds, the body of the projectile is painted a distinctive color, as follows:
*When the projectile is assembled with "Dark Ignition" tracers, a 1/8-inch bright red band will be painted around it midway between the bourrelet and the rotating band.
The Mark and Mod, manufacturer's initials or symbol, and lot number are stamped around the body of the projectile.
Abbreviations in Minor Calibers
H.E. --- High Explosive
I. --- Incendiary
T. --- Tracer
B.L. --- Blind Loaded
P. --- Plugged
S.D. --- Self-Destructive
D.I. --- Dark Ignition
Ammunition for Hispano-Suiza Gun
This gun and its ammunition are Army-designed but have been adopted as Naval equipment with the installation of the gun on Naval planes. The ammunition is distinguished from that designed for the Oerlikon gun by the extractor lip on the base of the cartridge, which is the same diameter as the rest of the case. Two series of ammunition for this gun are in use. The "Old Series" consists of unmatched rounds, some adapter from British prototype, others designed by the Army. The "New Series" is a set of ballistically matched rounds designed by the Army to supersede those of the "Old Series". For identification of the individual types of rounds, the body of the projectile is painted a distinctive color, as follows:
1.1"/75 Ammunition
The body of these projectiles, now obsolete items, were unpainted except for two dots below the fuze, indicating as follows:
Explosive D --- Yellow dot
Tracer --- Red dot
A newer color marking was proposed for the 1.1-inch ammunition. Some projectiles may be found painted as follows:
H.E.-T. -- Light Gray with White band
H.E.-T./S.D. -- Dark Green with White band
B.L. and P. -- Red overall
B.L. and T. -- Red overall with White band
40mm Ammunition
These projectiles are identified by distinctively colored bodies, as follows:
The tracer composition is either a red burning mixture in the tracer -- "T" rounds -- or a non-luminous burning compound in the "Self-Destructive" rounds.
"Dark" and "Dark Ignition Tracer": To eliminate the blinding effect on 40mm and 20mm gunners from tracer fire at night, and also to make the origin of tracer fire less distinct, these tracers were developed toward the close of the war. The dark ignition tracer is invisible until the projectile is 100 to 400 yards from the gun's muzzle, and then it is visible for the rest of its time of flight. Details of these tracers are described with their appropriate projectile and tracer housing.
Inert Fillers
(For details on explosive payloads, please see earlier updates in the US explosive updates)
Blind Loaded and Plugged (B.L. & P.): A projectile may be loaded with sand or other inert material and sealed with a solid base plug, or the tracer hole (fuze hole) in a base plug may be blanked off.
Blind Loaded and Tracer (B.L. & T.): These projectiles have an inert load, but a tracer is inserted in the fuze hole of the base plug.
White Phosphorus: An unstable smoke-incendiary agent, white phosphorus ignites when exposed to air and produces dense white smoke. It also has its incendiary, anti-personnel effect.
Gas: The various types of gas fillings are listed further below.
Color and Markings of new projectiles, 3-inch and larger
Explosive Indicator
Yellow ---- Explosive D
Grey ---- Black Powder
Green ---- TNT
1/2 Grey and 1/2 Green band ---- TNT and Black Powder mix
Red ---- Inert material or empty
Blue ---- Composition A
Time Fuze Stripe
Projectiles having a nose time fuze shall have a 1/4-inch white stripe painted longitudinally from the stationary lug on the fuze two inches aft.
Body Color
Black ---- AP
Slate Grey ---- Common
Green -- AA, HC, and AA Common
Light blue with two white stars ---- Illumination
Aluminum ---- Window
White ---- Shrapnel
Ocean Grey ---- Smoke, Gas, or Incendiary
Red ---- Targer ammunition
V.T. Fuzed
The letters "V.T." 3/4-inch high are stencilled just before the rear edge of the paint indicating the burster charge.
Tracer Band
A white band with four dots 90 degrees apart indicates the color of the tracer.
Spotting Band
The color indicates the color of the spotting charge.
"Window" Mark
This consists of a one-inch high "W" on each side, 180 degrees apart, just abaft the forward bourrelet.
Stenciling on Body
The following information is stenciled between the rotating band and the forward bourrelet on new projectiles:
-Ammunition lot number
-Caliber and type of projectile
-Mark and Mod of projectile
-Type nose fuze (whether MTF, PDF, VTF, Mk 32 and similar types, or Dummy Nose Plug)
-Mark and Mod of fuze
-Lot number of fuze (for Mk 32 and similar types only)
-Mark and Mod of auxiliary detonating fuze
-Mark and Mod of base detonating fuze
-Mark and Mod of tracer
-Color of tracer
-Mark and Mod of guns in which projectile can be used
-Mark and Mod of "Window" load
-Stamped on rotating band
-Mark and Mod of projectile
-Size and Type of projectile
-Lot number and year of specification
-Inspector's seal and initials
-Sometimes the manufacturer's name is included here
Stamped on base or on base plug
-Mark and Mod, size, and type of projectile
-Lot number, year of specification
-Inspector's seal and initial
-Manufacturer's name
The serial number of the projectile will also be stamped on the base plug on the side of the body, and on the windshield if present.
Chemical Filler Markings
Two green bands, 1/2-inch apart ---- Persistent casualty gas
One green band ---- Non-persistent casualty gas
One red band ---- Harassing gas
One yellow band ---- Smoke
One purple band ---- Incendiary
Also, on projectiles having a chemical filler, there is stenciled the type of chemical, such as SMOKE, INCENDIARY, or GAS, and the symbol or letter designating the particular filler.
Color and Marking of older projectiles, 3-inch and larger
In addition to the explosive filler, body color, spotting specifications, and base and band stamping mentioned above, the older projectiles had the following markings:
Tracer Band: White band with three dots, indicating tracer color, 120 degrees apart.
V.T. Fuzing: One-half inch red band painted one-half inch abaft the nose fuze.
Stenciled on the body
-Size, caliber, Mark and Mod of projectile
-Mark and Mod of fuzes
-Explosive filling and density of loading
-Abbreviated name of loading dept.
-Initials of Chief Inspector
-Date of filling and marking; any changes in filling, fuzing, etc.
Stamped on base
Weights before and after filling.
Next Time: 3-inch Projectiles
