The cartridge is used for proof testing of 20mm weapons and barrels during manufacture and repair. The cartridge is a solid steel projectile, under cut behind the ogive to control projectile weight, for developing high chamber pressure. The cartridge is identified by a stannic-stained (silvered) cartridge case.

The -A1 upgrade had a Mack ENDT-673, a 673 cu in (11.0 L) turbocharged inline 6 cylinder diesel engine developing 210 hp (160 kW) at 2100 rpm. The -A2 upgrade had a Continental LDS-465-1A, a 478 cu in (7.8 L) turbocharged inline 6 cylinder developing 175 hp (130 kW) at 2100 rpm.

They contain a substantial HE main charge and consequently have relatively thin to medium body-wall thickness. Their fragmentation effect results from fracture of the body wall on detonation of the main charge. They are or may be fitted with a variety of fuzes for effective use in engaging different types of targets.

Name: 20mm (20 x 102) HPT Cartridges M54A1. Hazard Class: 1.4S. DODIC/NSN: AA20/1305-01-448-9275. Part Numbering: 7258858 Cartridge. Description: High Pressure test ammunition for M39, M61 Vulcan, and M168 Weapon Systems. Brass M103 20 x 102mm case primed with M52 electric primer. Standard pack is 100 linked rounds per M548 Ammo can.

The base of the projectile is very thick (over 1 inch) and is tapered for streamlining purposes. The cavity for the shell-destroying tracer is machined into this heavy base. The bursting charge of 0.10 pound of is pressed into the body in two increments: a base pellet and a main charge. The M54 is painted olive drab and stenciled in yellow.

There are two main variants of the truck, the M54A1 (fitted with a Mack diesel engine) and the M54A2 (fitted with a Continental multifuel turbocharged engine). Other than the different engine types, the two trucks are identical.

Quad .50 gun truck mounted (4) M2 .50 caliber MG. Many also included an additional 7.62mm M60 Machine Gun. The M54 5-ton cargo truck was first produced from approximately 1952 to 1964 by Diamond-T, International Harvester and Mack. The M54 was equipped with the Continental R6602 gasoline engine.

INERT 20mm Vulcan M54A1 HPT (High Pressure Test) round with polished case. 20x102 Approx length 6.5", Approx width 1". Pictures are stock images of our inventory.

M54A1 CARGO TRUCK 6X6 LWB. NSN with winch: 2320-00-086-7482 NSN w/o winch: 2320-00-086-7481 TM numbers: 9-2320-211-Series (Nov 1977) Expanded Description: Horsepower: 205 bhp @ 2,100 rpm Transmission: Manual; 5 Fwd, 1 Rev VEHICLE DATA Type Classification & Date: Std B, 1963

Proof, M54A1: Projectile: steel, purple, 1 copper driving band Projectile Markings: (black ink) 20 MM HPT M54 A1 LC-SP-716 Driving Band Markings: GLN-1-4-68 M54A1: Case: brass, choke crimp Markings: (black ink) 20MM M103 RNO 1-932-68: Primer: electric, flat, brass, ring crimp, red annulus: Headstamp