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DispatchAccountMilitary

by The Unitary Technocracy of Etoile Arcture. . 103 reads.

MG78A1 General Purpose Machine Gun

This page is a work in progress by its author and should not be considered final.

MG78A1 General Purpose Machine Gun

Type

General-purpose
machine gun

Place of origin

Etoile Arcture

Service history

In service

2012 - present

Used by

Etoile Arcture
Ground Forces

Production history

Designer

Sequoia Weaponworks

Designed

2008-2011

Manufacturer

Sequoia Weaponworks

Unit cost

US$6,000

Number built

Plenty and lots

Variants

See below

Specifications

Weight

10.5 kg (23 lbs 2.377 oz)

Length

1397 mm (55 inches)

Barrel length

609 mm (24 inches)


Cartridge

7mm-08 Remington

Action

gas operated,
piston driven,
short stroke

Rate of fire

650-1,200 rounds/min

Muzzle velocity

900 m/s (2,953 ft/s)

Effective firing range

  • Bipod: 800 m
    (880 yd)

  • Tripod: 1,500 m
    (1,640 yd)

Maximum firing range

3,700 m (4,046 yd)

Feed system

M13-style
disintegrating metallic
split-linked belt

Sights

rear leaf and
hooded front post
w/ tritium inserts

The MG78A1 General Purpose Machine Gun (GPMG) is a gas-operated, locked-breech, air-cooled, belt-fed, sustained fire, sub-.30 calibre medium machine gun firing from the open-bolt position. It is chambered in the 7mm-08 Remington cartridge that is based on the .308 Winchester case necked down to accept a slimline 7 mm (.284 calibre) bullet. This chambering offers superior ballistic performance with a high ballistic coefficient bullet that delivers a flatter trajectory, moderate recoil for higher accuracy and lower muzzle blast, at a significant weight reduction in ammunition allowing more rounds to be carried per infantryman. The MG78A1 has applications including infantry ground mounting (on bipod or tripod), pintle/cradle and pedestal mountings with spade grips, as coaxial armament on armoured vehicles, and remote weapon stations.

Description


The MG78A1 is built on the short stroke gas operated rotating bolt operating system of the MG70B Universal Machine Gun platform. The weapon fires from the open bolt position in full automatic mode only. Its gas cylinder is located below the barrel, and operates the short stroke gas piston to drive a bolt carrier and rotating bolt. The bolt group, gas system and regulator are made from AISI 8620 chrome-plated alloy steel, and the breech and free-floating barrel from AISA 4140 chrome-moly high tensile steel that is double lapped and chrome lined for durability. A precision cast Stellite (high carbon cobalt alloy) liner is press-fitted into the chamber and rifling to further enhance wear resistance to extend barrel life. The receiver, M240-style buttstock, G500-style pistol grip/trigger guard and fore-end are made from high strength/heat resistant GF/PA-6 polyamide thermoplastics, which is moulded over a stamped and welded sheet-metal AISA 1018 low carbon steel reinforcement frame in the case of the receiver.
Linked ammunition can be fed from either 50 round loose belts that assemble together using a cartridge as an interlink to provide a continuous feed, or a nylon bandolier for 100 rounds clipped under the receiver for better handling characteristics. A high reliability single-stage feed mechanism strips rounds from M13-type push-through belt links to feed ammunition with a two-stage belt pull. The complete cycle of operation (feeding, chambering, locking, firing, unlocking, extracting, ejecting, and cocking) is performed from the open-bolt position for maximum cooling of the action. An adjustable gas regulator permits the cyclic rate to be varied at 650, 850 and 1,200 rpm to improve controllability, accuracy and barrel life during sustained firing, and provide additional power to overcome fouling in harsh conditions such as mud and dirt.
Features and improvements include: ambidextrous safety/selector levers, a folding bipod attached to the gas block, a tripod/pintle mounting lug, Stellite lined bore and breech for enhanced accuracy and service life, fixed head space and timing to allow fast barrel changes, an air-cooled quick-change barrel (QCB) assembly with integral carrying handle gas system, MIL-STD-1913 Picatinny accessory rails on the receiver feed tray cover for mounting sights, a straight line recoil path with the operating rod running directly to a spring-powered buffer system mounted in the fixed M240-style buttstock to reduce felt recoil, enlarged shell deflector and ejection ports with protective dust covers, an extended ventilated hand guard with forward rails, and a BE Meyers three port open-end flash hider that eliminates 93% of muzzle flash.

Variants


MG78A1 General Purpose Machine Gun

    Standard version chambered in the 7mm-08 Remington cartridge.

MG76E2 General Purpose Machine Gun

    Export variant chambered in 7.62x51mm NATO cartridge.

Users


Etoile Arcture

  • Etoile Arcture Ground Forces: provides the basis of fire at the platoon and company level.

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Specifications


  • Cartridge: 7mm-08 Remington

  • Action: gas operated, piston driven, short stroke

  • Locking: rotary bolt w/ 4 radial lugs

  • Weight: 11.5 kg fully loaded

  • Overall length: 1397 mm

  • Barrel length: 609 mm

  • Rifling: three lands and grooves, right hand twist, 1 turn in 241 mm

  • Muzzle device: three port open-end flash hider

  • Feed type: 100-round M13-style disintegrating metallic split-linked belt, nylon pouch-like drum magazine

  • Sights: rear leaf and hooded front post, day optics, etc

  • Muzzle velocity: 900 m/s

  • Effective range: 800 m vs point targets, 1,500 m vs area targets,

  • Maximum range: 3,700 m

  • Fire control: drop-in replaceable trigger group, ambidextrous selector levers

  • Rate of fire: 50-100 rpm practical, 650-1,200 rpm cyclic

  • Trigger pull: single-stage Match, non-adjustable 29.35 N pull

  • Unit replacement cost: US$1,500

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