CIS 50MG

CIS 50MG
The CIS 50MG on display during Singapore Army open house 2007.
Type	Heavy machine gun
Place of origin	Singapore
Service history
In service	1991–present
Used by	See Users
Production history
Designer	Chartered Industries of Singapore (CIS, now ST Kinetics)
Designed	Mid-1980s
Manufacturer	• CIS: 1988–2000 • ST Kinetics: 2000–present
Produced	1988–present
Specifications
Weight	30 kg (66.14 lb) (complete gun assembly w/o feed chute and tripod adaptor)
Length	1,778 mm (70.0 in) with stock
Barrel length	1,143 mm (45.0 in)
Width	190 mm (7.5 in)
Cartridge	12.7×99mm NATO
Barrels	Single barrel (progressive RH parabolic twist, 8 grooves)
Action	Gas-operated, rotating bolt
Rate of fire	400–600 rounds/min
Muzzle velocity	890 m/s (2,920 ft/s)
Feed system	Single sprocket Belt-fed with dual-feed chutes
Sights	Folding leaf sight

The CIS 50MG is a gas-operated, air-cooled, belt-fed heavy machine gun developed and manufactured by Chartered Industries of Singapore (CIS, now ST Kinetics) in the late 1980s, in response to a request by the Singaporean Defence Ministry to replace the 12.7mm Browning M2HB machine guns then in ubiquitous service with the Singapore Armed Forces (SAF).

The aim was to have a brand new heavy machine gun design, that fires the same type of .50 cal rounds as the M2HB machine guns and to have the gun parts more readily available in view of easing SAF's chain of logistics and supplies.

The CIS engineers learnt from the lesson of the canceled (lack of funding) American "Dover Devil GPHMG" program led by Mark K. Humphreville, to create a modular weapon suited for modern tactical doctrines and production techniques. In 1988, CIS introduced the new 12.7mm machine gun which was aptly named as the CIS 50MG, after two years of development and testing phase.

As the CIS 50MG is a gas-operated, air-cooled, belt-fed weapon, the gun is operated using dual gas pistons, located in two gas tubes placed on either side of the barrel. The barrel is locked by means of a rotary bolt with multiple radial lugs that engages the barrel extension, eliminating the need for headspace adjustments. The CIS 50MG utilises the same "constant recoil" system used in the Ultimax 100 and it also has a quick-detachable barrel equipped with a carrying handle to facilitate the ease of barrel changing under combat situations or during operational manoeuvres.

The one unique feature of the CIS 50MG is its dual belt-feed system, the system allows for fast and easy switching of ammunition from standard ball rounds to the Raufoss Mk 211 Armor-Piercing-Incendiary rounds or the Saboted light armor penetrator (SLAP), which are capable of penetrating a rolled homogeneous armour plate with a thickness of 25 mm (0.98 in) from a range of 1 km (0.62 mi).

Such systems are more commonly used in modern such as the M242 Bushmaster 25mm cannon and the Mk44 Bushmaster II 30mm cannon, both of which are also in use by the Singapore Army's Bionix AFVs.