Description
This cartridge is fired from 90mm gun cannons against armored targets.
The cartridge consists of a fin-stabilized steel projectile containing a high-explosive shaped charge and a brass cartridge case loosely filled with propellant. An inverted copper cone liner in the front of the projectile serves to shape the Composition B charge, and a streamlined windshield houses a piezoelectric element to initiate the point-initiating, base detonating fuze in the base. An obturator band encircles the projectile above the lip of the cartridge case. An igniter and fin assembly is threaded into the base of the projectile and extends the length of the cartridge case through the propelling charge. The igniter is a perforated shaft filled with 400 grains of black powder. The four fixed fins are attached to the base of the assembly, and the igniter tube is closed with a threaded retainer containing approximately 20 grains of black powder. The percussion primer is, in turn, threaded into the retainer, flush with the base of the cartridge case, and contains seven grains of black powder. The interior of the cartridge case is fitted with guided rails for the projectile fins. A filling plug is threaded into the base of the cartridge case for filling the case with the propelling charge after cartridge assembly.
The M348 has a cone tube extension which is not present in the M348A1. The fin cross-section of the M348 is rectangular while that of the M348A1 is T-shaped.
The projectile is painted olive drab with black markings.
Functioning
When the primer is struck by the firing pin of the weapon, the black powder is ignited through primer, retainer, and igniter to flash through the igniter perforations and ignite the propelling charge. Rapidly expanding gases from the burning propellant force the projectile through the gun barrel with a velocity of 2,800 feet per second. The obturator expands to prevent escape of gas pressure past the projectile while it is in the barrel, and the fins stabilize the projectile in flight. Upon impact with the target, distortion of the piezoelectric unit generates an electric current to initiate the fuze and detonate the explosive charge. As the copper cone is crushed, the detonation results in an intensely focused high velocity shock wave which causes failure of the target armor, and a jet of molten metal penetrates the target interior.
Hazardous Components
Filler - Composition B (1.56 lb, 0.71 kg)
Cartridge case - T27E2
Propelling charge - M6 (5 lb, 2.27 kg ); M1 (5.44 lb, 2.47 kg)
Primer - T69
Igniter, fin assembly - T33E2
Physical Data
Length, overall - 33.74 in, 857 mm
See Also
Cartridge, 90mm HEAT, M348A1 (T108E46)
Source(s)
TM 9-1300-203, Artillery Ammunition (1967)
