Faxon ARAK-21
- Category
- Rifle
- Barrel
- 406 mm
- Weight, empty
- 2.50 kg
- Introduced
- 2014
About
What it is, and why it matters
The Faxon ARAK-21 is a modular, AK-style long-stroke gas-piston upper receiver system that mounts on a standard AR-15 lower, blending the reliability of an AK operating system with the ergonomics and compatibility of the AR platform. Its monolithic 6061-T6 aluminum billet upper integrates a full-length Picatinny top rail with three additional rails at the muzzle end, an ambidextrous reciprocating side charging handle, and a user-adjustable long-stroke piston with three gas settings plus an off position for suppressed use. The XRS complete rifle ships ready to run with a Magpul SL stock, grip, ambidextrous safety, and a Radian Vertex trigger. The quick-change Barrel Assembly Unit lets the rifle swap between 5.56 NATO and 7.62x39mm, and the system is offered as 16-inch rifles and 12.5-inch pistols. The standard 16-inch configuration weighs about 5.5 pounds for the upper.
Faxon's ARAK-21 took its name and operating philosophy from the marriage of the AR and AK - a piston-driven, side-charging, quick-change-barrel upper that aimed to give AR shooters AK-grade reliability and easy caliber swaps without leaving the AR lower behind.
ARAK-21 upper mounts on any mil-spec AR-15 lower. Adjustable long-stroke piston with three gas settings plus suppressed/off. Quick-change barrel allows caliber conversion between 5.56 and 7.62x39. Available in anodized black or Cerakote FDE/OD. The XRS denotes the complete-rifle configuration with B5/Magpul furniture and Radian Vertex trigger.
Specification
Everything measured
IdentityWhat it is, who built it and when.
- Manufacturer
- Faxon Firearms
- Category
- Rifle
- Country
- United States
- Status
- In production
- Produced
- 2014
DimensionsAs issued, without a magazine or an optic.
- Barrel
- 406 mm
- Weight, empty
- 2.50 kg
ActionHow it cycles, what trips it, and what feeds it.
- Action
- Gas operated long stroke
- Firing mechanism
- Rotating bolt
- Trigger
- Single stage
- Trigger pull
- 27.0 N
- Capacity
- 30
- Magazine
- Detachable box
MaterialsEach swatch is the material itself, not a colour chosen to stand for it.
- Frame
- Aluminum alloy
- Barrel
- Steel
- Stock
- Polymer
- Finish
- Hard anodized
BallisticsFrom the service cartridge, not a handload.
- Effective range
- 500 m
- Maximum range
- 3600 m
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.
Adjustable gas system
Long stroke piston
Side charging handle
Ambidextrous charging handle
Quad rail
Picatinny rail
Quick change barrel
Monolithic upper
Rear ejection capable
Ar15 lower compatible
M lok rail
Collapsible stock
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 84 5.56x45mm NATO rifles | 2.50 kg | 3.08 kg | Among the lightest tenth |
| Barrel lengthAmong 98 5.56x45mm NATO rifles | 406 mm | 406 mm | Shorter than about 60% |
| Magazine capacityAmong 98 5.56x45mm NATO rifles | 30 | 30 | Near the median |
Its place in the rankings
Answers
Questions about the Faxon ARAK-21
How much does the Faxon ARAK-21 weigh?
The Faxon ARAK-21 weighs 2.50 kg (5.50 lb) empty. It is the 2nd lightest of 84 5.56x45mm NATO rifles in the catalogue.
What caliber is the Faxon ARAK-21?
The Faxon ARAK-21 is chambered in 5.56x45mm NATO and 7.62x39mm.
How many rounds does the Faxon ARAK-21 hold?
The Faxon ARAK-21 holds 30 rounds, fed from a detachable box magazine.
How long is the Faxon ARAK-21?
The Faxon ARAK-21 has a 406 mm (16.0 in) barrel.
Who makes the Faxon ARAK-21?
The Faxon ARAK-21 is made by Faxon Firearms (United States).
When was the Faxon ARAK-21 introduced?
The Faxon ARAK-21 was introduced in 2014.
How does the Faxon ARAK-21 operate?
The Faxon ARAK-21 uses a gas operated long stroke action, and its firing mechanism is rotating 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.
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/faxon-arak-21' \ --header 'X-API-Key: your_key'{ "id": "faxon-arak-21", "name": "Faxon ARAK-21", "manufacturer": { "id": "faxon-firearms", "name": "Faxon Firearms", "countryCode": "US", "foundedYear": 2010, "website": "https://faxonfirearms.com", "logoUrl": null, "description": null, "status": null, "defunctYear": null, "stateOwned": null, "makesFirearms": null, "parentId": null, "predecessorId": null, "createdAt": "2026-05-26 23:17:02", "updatedAt": "2026-05-26 23:17:02", "version": "d8d87003d1656ba37045f0618b96762c150bb1e2337c1cbfae5a424229504615" }, "category": { "id": "rifle", "name": "Rifle", "description": "Long-barreled firearms designed for accurate shooting" }, "country_of_origin": "US", "year_introduced": 2014, "barrel_length_mm": 406, "weight_empty_g": 2495, "action_type": "gas_operated_long_stroke"}