Description
This fixed ammunition is used in 40mm gun cannons for firing against materiel.
The relatively thin-walled projectile contains a burster charge, an incendiary charge, a point-detonating fuze, and a self-destroying (SD) tracer. The projectile nose is threaded to receive the fuze. The SD tracer assembly is contained in the boat-tailed base of the projectile, which is internally threaded, and it extends approximately 0.6 inch beyond the base. The SD tracer consists of an igniting charge, a red tracer composition, and a relay igniting charge. The cartridge case, either brass or steel, is crimped rigidly to the projectile by means of a 360° crimp. The base of the cartridge case contains a percussion primer consisting of a perforated tube containing black powder and a percussion element.
Cartridges manufactured by the Navy may be distinguished by the painting on the fuzes. The fuze for the Navy HEI-T cartridge is painted red and white (red tip on fuze).
Functioning
When the firing pin of the weapon strikes the percussion primer, the black powder in the primer tube is ignited. Sparks from the black powder ignite the propellant charge to impart velocity to the projectile and to ignite the tracer. The high explosive bursting charge is detonated either by the fuze upon contact with the target, or by the tracer relay igniting charge. The tracer composition burns with a visible trace for 8 to 10 seconds.
Hazardous Components
Filler - TNT (0.14 lb, 0.06 kg)
Tracer incendiary charge (36 grains)
Propellant - M1 (0.72 lb, 0.33 kg)
Primer - Mk 22, M38A1, M38B2
Burster charge - TNT powder and incendiary charge
Physical Data
Length, overall - 17.6 in, 447 mm
See Also
Source(s)
TM 43-0001-28, Artillery Ammunition (chg 11, 2003)
TM 9-1300-203, Artillery Ammunition (1967)
