CIS 50MG
- Category
- Machine Gun
- Barrel
- 1141 mm
- Weight, empty
- 30.00 kg
- Introduced
- 1991
About
What it is, and why it matters
The CIS 50MG (now STK 50MG) is a Singaporean heavy machine gun chambered in 12.7x99mm NATO (.50 BMG), developed by Chartered Industries of Singapore to replace the ageing Browning M2HB. It is gas-operated with a rotating bolt and a quick-change barrel, and is notable for its dual-belt feed system that lets the gunner switch between two ammunition types - for example armour-piercing and high-explosive - without unloading the weapon.
Unusual among heavy machine guns, the CIS 50MG carries two ammunition belts at once - a gunner can flick a selector to switch from armour-piercing to high-explosive incendiary rounds mid-engagement without ever reloading.
Indonesia produces the design under licence as the SMB-QCB. The weapon can be mounted on tripods, vehicles and a soft-recoil cradle.
Specification
Everything measured
IdentityWhat it is, who built it and when.
- Manufacturer
- ST Engineering Land Systems
- Category
- Machine Gun
- Country
- Singapore
- Status
- In production
- Produced
- 1991
DimensionsAs issued, without a magazine or an optic.
- Barrel
- 1141 mm
- Overall length
- 1670 mm
- Weight, empty
- 30.00 kg
ActionHow it cycles, what trips it, and what feeds it.
- Action
- Gas operated long stroke
- Firing mechanism
- Open bolt
- Magazine
- Belt
MaterialsEach swatch is the material itself, not a colour chosen to stand for it.
- Frame
- Steel
- Barrel
- Steel
- Finish
- Phosphate
BallisticsFrom the service cartridge, not a handload.
- Muzzle velocity
- 884 m/s
- Muzzle energy
- 16370 J
- Effective range
- 1500 m
- Maximum range
- 6800 m
- Rate of fire
- 500 rpm
Trajectory
What the round does downrange
Solved from the muzzle figures and the bullet. The dashed rule is the effective range on the record, and the crosses are the steps the solver returned.
Features
What it has
What the record lists as fitted, drawn from the catalogue.
Dual belt feed
Quick change barrel
Rotating bolt- Tripod mountable
- Fixed headspace
Soft recoil mount
Standing
How it compares
Each figure against the firearms of the same type and cartridge that record it, or of the same type where that cartridge has too few. Positions are read to the nearest tenth.
| Measurement | This firearm | Median | Position |
|---|---|---|---|
| Empty weightAmong 261 machine guns | 30.00 kg | 10.50 kg | Heavier than about 90% |
| Overall lengthAmong 260 machine guns | 1670 mm | 1156 mm | Longer than about 90% |
| Barrel lengthAmong 257 machine guns | 1141 mm | 605 mm | Longer than about 90% |
Answers
Questions about the CIS 50MG
How much does the CIS 50MG weigh?
The CIS 50MG weighs 30.00 kg (66.14 lb) empty.
What caliber is the CIS 50MG?
The CIS 50MG is chambered in .50 BMG.
How long is the CIS 50MG?
The CIS 50MG is 1670 mm (65.7 in) long overall, with a 1141 mm (44.9 in) barrel.
Who makes the CIS 50MG?
The CIS 50MG is made by ST Engineering Land Systems (Singapore).
When was the CIS 50MG introduced?
The CIS 50MG was introduced in 1991.
How does the CIS 50MG operate?
The CIS 50MG uses a gas operated long stroke action, and its firing mechanism is open bolt.
Compatibility
Which parts fit this firearm
Studio
Every part that mounts on this, resolved
Not a list the maker typed out: the answer comes from the mounts this firearm exposes and the interface each part needs, so it stays right when either one changes.
- Every part that mounts on any firearm in the catalogue
- Interface standards, platforms and fit overrides
- The same answers through the API and the MCP server
Requires a signed-in GunSpec account on the Studio plan. The answer is computed per part, so it is not part of the public record.
Provenance
What the record holds
Every figure above was taken from one of these pages. The confidence reflects how much of the record came from a page a claim can be checked against.
In service
- Singapore Armed Forces
- 1991
- Indonesian National Armed Forces
- Indonesia
Provenance
Confidence in this record
74%
Stockists
Where to buy
Offers link straight to the shop. GunSpec never takes the order.
No shop has listed this firearm yet
Stock and prices come from the shops themselves. If you sell this firearm, you can list it and it appears here.
List a firearmMCP
Ask an assistant about it
The same record, reached the way a person asks for it rather than the way a program does.
Ask GunSpec
Works with
Point an MCP client at GunSpec and it answers from the catalogue rather than from memory. A free key covers the read tools.
API
The call that returns this record
The same fields, in the same units, from the same endpoint the page reads.
curl --request GET \ --url 'https://api.gunspec.io/v1/firearms/cis-50mg' \ --header 'X-API-Key: your_key'{ "id": "cis-50mg", "name": "CIS 50MG", "manufacturer": { "id": "st-kinetics", "name": "ST Engineering Land Systems", "countryCode": "SG", "foundedYear": 1967, "website": "https://www.stengg.com", "logoUrl": null, "description": "Singapore defense contractor specializing in armored vehicles and ground combat systems. Historically produced small arms including the Ultimax 100 light machine gun and SAR 21 bullpup rifle.", "status": "active", "defunctYear": null, "stateOwned": null, "makesFirearms": true, "parentId": null, "predecessorId": null, "createdAt": "2026-02-18 03:40:48", "updatedAt": "2026-09-15 07:19:19", "version": "60b09a84aaed1bb6ff46e4d8f29b675171e7f36c2772f1aafc8dcf4bf0262e2e" }, "category": { "id": "machine-gun", "name": "Machine Gun", "description": "Fully automatic firearms for sustained fire" }, "country_of_origin": "SG", "year_introduced": 1991, "barrel_length_mm": 1141, "weight_empty_g": 30000, "action_type": "gas_operated_long_stroke"}