AREX Rex Delta X
- Category
- Pistol
- Barrel
- 102 mm
- Weight, empty
- 539 g
- Introduced
- 2022
About
What it is, and why it matters
The AREX Rex Delta X is a full-size striker-fired semi-automatic pistol chambered in 9x19mm Parabellum, produced by the Slovenian manufacturer AREX Defense. Part of the modular Rex Delta family, the Delta X pairs a polymer frame with a 4-inch (102 mm) barrel and a 17-round detachable box magazine, and is offered in an optics-ready (OR) configuration for mounting a micro red-dot sight. Its short-recoil, locked-breech action drives a partially pre-cocked striker, and the frame accepts removable front and rear inserts plus interchangeable backstraps for fitting the grip to the shooter. Ambidextrous slide stops, a reversible magazine release, a flared magwell, an accessory rail, and both forward and rear slide serrations round out a practical duty and defensive handgun.
AREX built its reputation on the full-metal Rex Zero 1 service pistol before moving into the polymer, striker-fired market with the Delta; the modular Delta X lets a shooter reconfigure grip size and add a red-dot without changing the frame or slide's internal architecture.
The Delta line is offered in three grip/slide sizes — M (compact), X (mid/standard) and L (full length) — each available in a standard or optics-ready (OR) version. The Delta X is the modernized, modular successor to AREX's earlier Delta pistol.
Specification
Everything measured
IdentityWhat it is, who built it and when.
- Manufacturer
- AREX Defense
- Category
- Pistol
- Country
- Slovenia
- Status
- In production
- Produced
- 2022
DimensionsAs issued, without a magazine or an optic.
- Barrel
- 102 mm
- Overall length
- 183 mm
- Height
- 130 mm
- Width
- 30 mm
- Weight, empty
- 539 g
- Weight, loaded
- 624 g
ActionHow it cycles, what trips it, and what feeds it.
- Action
- Short recoil
- Firing mechanism
- Striker fired
- Trigger
- Single action
- Trigger pull
- 27.0 N
- Capacity
- 17
- Magazine
- Detachable box
MaterialsEach swatch is the material itself, not a colour chosen to stand for it.
- Frame
- Polymer
- Slide
- Steel
- Barrel
- Steel
- Finish
- Nitride
BallisticsFrom the service cartridge, not a handload.
- Muzzle velocity
- 360 m/s
- Muzzle energy
- 481 J
- Effective range
- 50 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.
Optics ready
Removable front and rear frame inserts- Interchangeable grip inserts
Flared magwell
Accessory rail
Ambidextrous slide stop
Reversible magazine release
Forward and rear slide serrations
Stippled grip
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 560 9x19mm Parabellum pistols | 539 g | 765 g | Lighter than about 90% |
| Overall lengthAmong 559 9x19mm Parabellum pistols | 183 mm | 191 mm | Shorter than about 70% |
| Barrel lengthAmong 569 9x19mm Parabellum pistols | 102 mm | 105 mm | Shorter than about 60% |
| Magazine capacityAmong 571 9x19mm Parabellum pistols | 17 | 15 | Holds more rounds than about 80% |
Answers
Questions about the AREX Rex Delta X
How much does the AREX Rex Delta X weigh?
The AREX Rex Delta X weighs 539 g (1.19 lb) empty and 624 g (1.38 lb) loaded.
What caliber is the AREX Rex Delta X?
The AREX Rex Delta X is chambered in 9x19mm Parabellum.
How many rounds does the AREX Rex Delta X hold?
The AREX Rex Delta X holds 17 rounds, fed from a detachable box magazine.
How long is the AREX Rex Delta X?
The AREX Rex Delta X is 183 mm (7.20 in) long overall, with a 102 mm (4.02 in) barrel.
Who makes the AREX Rex Delta X?
The AREX Rex Delta X is made by AREX Defense (Slovenia).
When was the AREX Rex Delta X introduced?
The AREX Rex Delta X was introduced in 2022.
How does the AREX Rex Delta X operate?
The AREX Rex Delta X uses a short recoil action, and its firing mechanism is striker 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
68%
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/arex-rex-delta-x' \ --header 'X-API-Key: your_key'{ "id": "arex-rex-delta-x", "name": "AREX Rex Delta X", "manufacturer": { "id": "arex", "name": "AREX Defense", "countryCode": "SI", "foundedYear": 1997, "website": "https://www.arex.si", "logoUrl": null, "description": null, "status": null, "defunctYear": null, "stateOwned": null, "makesFirearms": null, "parentId": null, "predecessorId": null, "createdAt": "2026-02-18 03:40:42", "updatedAt": "2026-02-18 03:43:38", "version": "0ed9d142216c5e0ead80ad705efceecaa3d258b82ff13aef9fc24051eefef685" }, "category": { "id": "pistol", "name": "Pistol", "description": "Handguns designed to be fired with one or two hands" }, "country_of_origin": "SI", "year_introduced": 2022, "barrel_length_mm": 102, "weight_empty_g": 539, "action_type": "short_recoil"}