ARWEN 37
- Category
- Rifle
- Barrel
- 310 mm
- Weight, empty
- 3.10 kg
- Introduced
- 1981
About
What it is, and why it matters
The ARWEN 37 (Anti-Riot Weapon ENfield) is a British gas-operated, five-shot less-lethal launcher developed by the Royal Small Arms Factory at Enfield in the late 1970s and introduced in 1981. Firing 37mm munitions from a rifled barrel and a five-round rotary cylinder, it delivers direct-impact baton rounds as well as chemical-irritant and smoke projectiles for crowd control. The multi-shot rotary design gave riot police and military units a rapid, repeatable less-lethal capability that single-shot launchers of the era lacked.
The ARWEN 37's name is a backronym for Anti-Riot Weapon ENfield, a play on the elf-maiden Arwen from J.R.R. Tolkien's Middle-earth. It was conceived to give British forces in Northern Ireland a multi-shot alternative to single-fire baton guns.
Named as an acronym for Anti-Riot Weapon ENfield, echoing the Tolkien character Arwen. The rifled barrel spin-stabilises baton rounds for improved accuracy over smoothbore riot guns.
Specification
Everything measured
IdentityWhat it is, who built it and when.
- Manufacturer
- Royal Small Arms Factory
- Category
- Rifle
- Country
- United Kingdom
- Status
- In production
- Produced
- 1981
DimensionsAs issued, without a magazine or an optic.
- Barrel
- 310 mm
- Overall length
- 840 mm
- Weight, empty
- 3.10 kg
ActionHow it cycles, what trips it, and what feeds it.
- Action
- Gas operated
- Firing mechanism
- Hammer fired
- Trigger
- Double action
- Capacity
- 5
- Magazine
- Revolving cylinder
MaterialsEach swatch is the material itself, not a colour chosen to stand for it.
- Frame
- Steel
- Barrel
- Steel
- Stock
- Polymer
- Finish
- Matte black
BallisticsFrom the service cartridge, not a handload.
- Muzzle velocity
- 74 m/s
- Effective range
- 100 m
- Rate of fire
- 60 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.
No load solved for this record yetThe flight path is computed from a cartridge and a bullet. This record has no ammunition filed against its chambering, so there is nothing to solve.
Features
What it has
What the record lists as fitted, drawn from the catalogue.
Five round rotary cylinder
Rifled barrel
Adjustable stock
Pistol grip
Carrying handle sight
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 1,612 rifles | 3.10 kg | 3.50 kg | Lighter than about 70% |
| Overall lengthAmong 1,557 rifles | 840 mm | 1080 mm | Shorter than about 90% |
| Barrel lengthAmong 1,659 rifles | 310 mm | 584 mm | Shorter than about 90% |
| Magazine capacityAmong 1,611 rifles | 5 | 5 | Holds more rounds than about 60% |
Answers
Questions about the ARWEN 37
How much does the ARWEN 37 weigh?
The ARWEN 37 weighs 3.10 kg (6.83 lb) empty.
What caliber is the ARWEN 37?
The ARWEN 37 is chambered in 37mm Less-Lethal.
How many rounds does the ARWEN 37 hold?
The ARWEN 37 holds 5 rounds, fed from a revolving cylinder.
How long is the ARWEN 37?
The ARWEN 37 is 840 mm (33.1 in) long overall, with a 310 mm (12.2 in) barrel.
Who makes the ARWEN 37?
The ARWEN 37 is made by Royal Small Arms Factory (United Kingdom). It was designed by Royal Small Arms Factory, Enfield.
When was the ARWEN 37 introduced?
The ARWEN 37 was introduced in 1981.
How does the ARWEN 37 operate?
The ARWEN 37 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
- British Armed Forces
- United Kingdom
- United Kingdom police forces
- United Kingdom
- Canadian law enforcement
- Canada
- French law enforcement
- France
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/arwen-37' \ --header 'X-API-Key: your_key'{ "id": "arwen-37", "name": "ARWEN 37", "manufacturer": { "id": "royal-small-arms-factory", "name": "Royal Small Arms Factory", "countryCode": "GB", "foundedYear": 1816, "website": null, "logoUrl": null, "description": null, "status": null, "defunctYear": null, "stateOwned": null, "makesFirearms": null, "parentId": null, "predecessorId": null, "createdAt": "2026-04-05 22:24:37", "updatedAt": "2026-04-05 22:24:37", "version": "cc7e952d6e6fac881044862f14fe6925a2806206d419f090a4b5fea3fe05740a" }, "category": { "id": "rifle", "name": "Rifle", "description": "Long-barreled firearms designed for accurate shooting" }, "country_of_origin": "GB", "year_introduced": 1981, "barrel_length_mm": 310, "weight_empty_g": 3100, "action_type": "gas_operated"}