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Navigation: Ordnance > Projectiles > United States

US Cartridge, 105mm Illuminating, M314, M314A2, M314A2B1

Description

These are howitzer fired base ejection cartridges with a parachute retarded illuminating canister installed. The M314A3 projectile uses the M565, M577, or the M724 fuzes. The M314, M314A1, & M314A2 use the M501 series fuze.

The M314 series projectile could have a gray body with white band and white marking, or a white body with black markings. The caliber, shell designation, lot number, and date of manufacture are stamped into the projectile bodies, just forward of the rotating band.

The projectile is a hollow steel forging with a streamlined ogive, gilding metal rotating band, and pinned base plug. The projectile is assembled with an MTSQ fuze threaded into the nose of the projectile. The projectile cavity contains the expelling charge, illuminating canister, and parachute assembly. The expelling charge consists of 0.11 lb of black powder contained in a cloth bag. The illuminating canister contains the illuminant and 0.15 lb of first-fire composition. The parachute assembly is attached to the illuminating canister body. The base plug is inserted into the opening at the base of the projectile and held in place by three shear pins and three twist pins. The complete projectile is free-fitted to a cartridge case. The cartridge case contains a percussion primer assembly and seven individually bagged and numbered propelling charge increments. The base of the cartridge case is drilled and the primer assembly is pressed into the base. The percussion primer assembly consists of a percussion ignition element and a perforated flash tube containing black powder. The seven numbered increments bags are tied together, in numerical order, with acrylic cord. These are assembled into the cartridge case, around the primer flash tube, with Increment 1 at the base of the cartridge case and Increment 7 toward the mouth of the cartridge case.

These cartridges are similar to the M314A2E1 cartridge except that they are not fitted with anti-rotational brakes and the expelling charge is contained in a cloth bag rather than a sealed plastic holder. These cartridges also differ from the M314A2E1 ballistically, with a muzzle velocity of 1535 feet-per-second and a maximum range of 10,447 yards. The projectile body may be fabricated from a one-piece steel forging or a steel tubing with a threaded nose adapter.

Functioning

If the projectile is unfuzed, both the closing plug and the fuze assembly to the projectile are removed prior to adjusting the charge and loading the cartridge into the weapon. Impact of the weapon firing pin results in the initiation of the percussion primer which, in turn, ignites the black powder in the flash tube. The flash tube provides for uniform ignition of the propelling charge producing a rapid expansion of the propellant gas which propels the projectile out of the weapon tube. Engagement of the projectile rotating band with the rifling of the weapon tube imparts spin to the projectile providing inflight stability. The MTSQ fuze functions and ignites the expelling charge, and in turn, ignites the first-fire composition. The expelling charge ejects the illumination canister and parachute assembly from the base of the projectile by blowing off the base plug. Concurrently, the parachute deploys and inflates, and the illuminant is ignited by the first-fire composition.

Canister M316A1 has an intensity of 600,000 foot candles for approximately 60 seconds. Canister M316 burns for approximately 40 seconds with a light intensity of 240,000 foot candles.