FAMAE SG 540
- Category
- Assault Rifle
- Barrel
- 460 mm
- Weight, empty
- 3.26 kg
- Introduced
- 1981
About
What it is, and why it matters
The FAMAE SG 540 is a Chilean-built, gas-operated, selective-fire assault rifle chambered in 5.56x45mm NATO, produced under license from SIG by Chile's state arms manufacturer FAMAE. It retains the original Swiss design: a long-stroke gas piston driving a rotating two-lug bolt, an adjustable three-position gas regulator, a side-folding tubular stock, an integral folding bipod, and a drum-type rear sight. License production let the Chilean Armed Forces standardize on a domestically manufactured 5.56mm service rifle, and FAMAE continued building the type after SIG ended its own production.
When Chile sought a modern domestic service rifle, FAMAE licensed SIG's export-oriented SG 540 rather than developing one from scratch. The rifle armed the Chilean Army for decades and became the technical foundation for FAMAE's later indigenous small arms, including the SAF submachine gun derived from the same SG 540 mechanism.
FAMAE manufactured the SG 540 under SIG license for the Chilean Army, later offering the improved SG 540-1 with a fixed stock. Experience producing the SG 540 fed directly into FAMAE's own SAF submachine gun and later FD-200/FAMAE rifle developments.
Specification
Everything measured
IdentityWhat it is, who built it and when.
- Manufacturer
- Fábricas y Maestranzas del Ejército (FAMAE)
- Category
- Assault Rifle
- Country
- Chile
- Status
- In production
- Produced
- 1981
- Variant of
- License production
DimensionsAs issued, without a magazine or an optic.
- Barrel
- 460 mm
- Overall length
- 950 mm
- Weight, empty
- 3.26 kg
ActionHow it cycles, what trips it, and what feeds it.
- Action
- Gas operated
- Firing mechanism
- Hammer fired
- Trigger
- Single action
- Capacity
- 30
- Magazine
- Detachable box
MaterialsEach swatch is the material itself, not a colour chosen to stand for it.
- Frame
- Steel
- Barrel
- Steel
- Stock
- Polymer
- Finish
- Phosphate
BallisticsFrom the service cartridge, not a handload.
- Muzzle velocity
- 980 m/s
- Effective range
- 500 m
- Rate of fire
- 750 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.
Gas piston operation
Rotating bolt
Adjustable gas regulator
Side folding stock
Integral folding bipod
Drum rear sight- Rifle grenade compatible
Nato muzzle device
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 158 5.56x45mm NATO assault rifles | 3.26 kg | 3.60 kg | Lighter than about 80% |
| Overall lengthAmong 156 5.56x45mm NATO assault rifles | 950 mm | 920 mm | Longer than about 60% |
| Barrel lengthAmong 157 5.56x45mm NATO assault rifles | 460 mm | 449 mm | Longer than about 70% |
| Magazine capacityAmong 158 5.56x45mm NATO assault rifles | 30 | 30 | Near the median |
Answers
Questions about the FAMAE SG 540
How much does the FAMAE SG 540 weigh?
The FAMAE SG 540 weighs 3.26 kg (7.19 lb) empty.
What caliber is the FAMAE SG 540?
The FAMAE SG 540 is chambered in 5.56x45mm NATO.
How many rounds does the FAMAE SG 540 hold?
The FAMAE SG 540 holds 30 rounds, fed from a detachable box magazine.
How long is the FAMAE SG 540?
The FAMAE SG 540 is 950 mm (37.4 in) long overall, with a 460 mm (18.1 in) barrel.
Who makes the FAMAE SG 540?
The FAMAE SG 540 is made by Fábricas y Maestranzas del Ejército (FAMAE) (Chile). It was designed by Schweizerische Industrie Gesellschaft (SIG).
When was the FAMAE SG 540 introduced?
The FAMAE SG 540 was introduced in 1981.
How does the FAMAE SG 540 operate?
The FAMAE SG 540 uses a gas operated action, and its firing mechanism is hammer fired.
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
- Chilean Army
- 1981
- Carabineros de Chile
- Chile
Provenance
Confidence in this record
78%
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/famae-sg-540' \ --header 'X-API-Key: your_key'{ "id": "famae-sg-540", "name": "FAMAE SG 540", "manufacturer": { "id": "famae", "name": "Fábricas y Maestranzas del Ejército (FAMAE)", "countryCode": "CL", "foundedYear": 1811, "website": "https://www.famae.cl", "logoUrl": null, "description": null, "status": null, "defunctYear": null, "stateOwned": null, "makesFirearms": null, "parentId": null, "predecessorId": null, "createdAt": "2026-07-06 11:00:16", "updatedAt": "2026-07-06 11:00:16", "version": "ea72fc6dbfeed7236dca37a093885643258887d3f50d80ba37eafbacb3adf90b" }, "category": { "id": "assault-rifle", "name": "Assault Rifle", "description": "Selective-fire rifles chambered in intermediate cartridges" }, "country_of_origin": "CL", "year_introduced": 1981, "barrel_length_mm": 460, "weight_empty_g": 3260, "action_type": "gas_operated"}