AYA No. 4
- Category
- Shotgun
- Barrel
- 711 mm
- Weight, empty
- 2.95 kg
- Introduced
- 1958
About
What it is, and why it matters
The AYA No. 4 is a Spanish hammerless boxlock ejector side-by-side double-barrelled shotgun built by Aguirre y Aranzabal of Eibar. Based on the classic Anson & Deeley boxlock action, it is the simplest and most robust of the firm's best-quality game guns, using disc-set firing pins, chopper-lump barrels, automatic ejectors, double triggers with a hinged front trigger and an automatic safety. Offered in 12, 16, 20 and 28 gauge and .410 bore, the No. 4 pairs straightforward boxlock mechanics with English scroll engraving and a straight-hand walnut stock, making it a popular affordable best-quality boxlock game gun.
Aguirre y Aranzabal was founded in 1917 in Eibar by Nicolas Aranzabal and the Aguirre brothers. The No. 4 boxlock sits below the firm's sidelock No. 1 and No. 2 models, offering the same chopper-lump barrels and best-quality finish on the simpler, hard-wearing Anson & Deeley action.
Standard barrel length is 28 inches with other lengths and choke configurations available to order; proofed for the 2.75 inch (70mm) cartridge. Weight is approximately 6 lb in 20 bore and just under 7 lb in 12 bore. The De Luxe version adds a Churchill-style tapered rib, upgraded wood and finer engraving. Unlike the sidelock No. 1 and No. 2, the No. 4 uses a boxlock action.
Specification
Everything measured
IdentityWhat it is, who built it and when.
- Manufacturer
- Aguirre y Aranzabal S.A.L.
- Category
- Shotgun
- Country
- Spain
- Status
- In production
- Produced
- 1958
DimensionsAs issued, without a magazine or an optic.
- Barrel
- 711 mm
- Overall length
- 1143 mm
- Weight, empty
- 2.95 kg
ActionHow it cycles, what trips it, and what feeds it.
- Action
- Break action
- Firing mechanism
- Hammer fired
- Trigger
- Double trigger
- Capacity
- 2
- Magazine
- Internal
MaterialsEach swatch is the material itself, not a colour chosen to stand for it.
- Frame
- Steel
- Barrel
- Steel
- Stock
- Walnut
- Finish
- Color case hardened
BallisticsFrom the service cartridge, not a handload.
- Muzzle velocity
- 381 m/s
- Muzzle energy
- 2030 J
- Effective range
- 40 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.
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.
Boxlock
Anson and deeley action
Side by side barrels
Double trigger
Automatic ejectors
Chopper lump barrels
Disc set firing pins
Churchill rib
English scroll engraving
Straight hand stock
Fixed chokes
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 755 shotguns | 2.95 kg | 3.25 kg | Lighter than about 80% |
| Overall lengthAmong 678 shotguns | 1143 mm | 1150 mm | Shorter than about 60% |
| Barrel lengthAmong 782 shotguns | 711 mm | 711 mm | Longer than about 60% |
| Magazine capacityAmong 777 shotguns | 2 | 3 | Holds fewer rounds than about 70% |
Answers
Questions about the AYA No. 4
How much does the AYA No. 4 weigh?
The AYA No. 4 weighs 2.95 kg (6.50 lb) empty.
What caliber is the AYA No. 4?
The AYA No. 4 is chambered in 16 Gauge.
How many rounds does the AYA No. 4 hold?
The AYA No. 4 holds 2 rounds, fed from an internal magazine.
How long is the AYA No. 4?
The AYA No. 4 is 1143 mm (45.0 in) long overall, with a 711 mm (28.0 in) barrel.
Who makes the AYA No. 4?
The AYA No. 4 is made by Aguirre y Aranzabal S.A.L. (Spain). It was designed by Aguirre y Aranzabal.
When was the AYA No. 4 introduced?
The AYA No. 4 was introduced in 1958.
How does the AYA No. 4 operate?
The AYA No. 4 uses a break 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.
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/aya-no-4' \ --header 'X-API-Key: your_key'{ "id": "aya-no-4", "name": "AYA No. 4", "manufacturer": { "id": "aya", "name": "Aguirre y Aranzabal S.A.L.", "countryCode": "ES", "foundedYear": 1917, "website": "https://www.aya-fineguns.com", "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": "6a4c05ed1c8fbec52652e5e2741497cb21531be28c5e55bb77458b63a5f11222" }, "category": { "id": "shotgun", "name": "Shotgun", "description": "Smoothbore firearms designed to fire shot or slugs" }, "country_of_origin": "ES", "year_introduced": 1958, "barrel_length_mm": 711, "weight_empty_g": 2950, "action_type": "break_action"}