projectile, except it incorporates a tracer in the base of
The M242 projectile is used with the M242
cartridge. The projectile has a tracer in the base and
aluminized composition A-4 in the forward section. It
has a combined effect of a high-explosive charge plus a
fire-starting ability. The projectile is assembled with
the M505A3 PD fuze, the M103 case, and the
M52A3B1 electric primer.
Ammunition is identified by the color the projectile
is painted and by the lettering on the body of the
The lettering (fig. 7-4) is stenciled in waterproof
marking ink around the body of the projectile. The first
line of lettering identifies the caliber and type of
cartridge; for example, 20MM HEI, 20MM TP, or
20MM HEI-T. The second line gives the cartridge
designation; for example, M254, M55A2, or M220.
The last line consists of a code number that identifies
the manufacturer, interfix number, lot serial number,
and year of manufacture. The color of the letters has no
The color codes for the M50-configured 20-mm
ammunition are listed in table 7-2. You can see exactly
where colors are located on the projectile. The
projectile (fig. 7-4) is divided into sections marked A,
B, C, and D. The sections on the projectile match the
color code to columns in the figure.
By looking at table 7-2, you can identify
high-explosive incendiary-tracer round M242. First,
find the projectile and its color code in column A. Then,
look at section A of the projectile. This section of the
projectile isn't painted; therefore, section A of the
projectile remains the natural color of the metal
(copper). Look at column B and find the color for
section B. Refer to section B of the projectile. This area
is painted yellow (high explosives), and section B1 is
painted red (incendiary). Use the same procedures for
sections C and D. Also note the red T markings in the
section B area just outside of the B1 section. The red T,
and in some cases orange T, shows the presence of an
incendiary explosive (tracer).
PGU CONFIGURATION AMMUNITION
ammunition for the M61A1/A2 aircraft guns is issued
in the form of cartridges (fig 7-5). All service cartridges
have matched ballistics and are electrically primed.
Initially procured ammunition is not graded, and all
accepted lots are serviceable for issue and use in
The PGU configuration ammunition currently
issued is classified as follows:
Target Practice Cartridge PGU-27/B
Incendiary Cartridge PGU-28/B (SAPHEI)
Target Practice-Tracer Cartridge PGU-30/B
CARTRIDGE COMPONENTS, GENERAL
The cartridge components for PGU-configured
ammunition as used in a complete round are discussed
in the following paragraphs.
Figure 7-5.PGU configuration cartridge.