Daniel Defense MK18 RIII
- Category
- Carbine
- Barrel
- 262 mm
- Weight, empty
- 2.60 kg
- Introduced
- 2024
About
What it is, and why it matters
The MK18 RIII evolves the legendary MK18 platform with a fully ambidextrous lower receiver and the new RIS III M-LOK handguard. Both left- and right-handed shooters can operate the bolt catch, safety selector, and magazine release without breaking their shooting grip. The slimmer M-LOK handguard reduces weight while maintaining the 10.3-inch barrel that defined the CQB standard.
The RIII series represents Daniel Defense's next generation, replacing the iconic quad rail with a lighter M-LOK handguard while adding fully ambidextrous controls demanded by modern military and law enforcement users.
MSRP: $2,554. NFA-regulated SBR. The RIII designation indicates the RIS III handguard system replacing the quad rail.
Specification
Everything measured
IdentityWhat it is, who built it and when.
- Manufacturer
- Daniel Defense
- Category
- Carbine
- Country
- United States
- Status
- In production
- Produced
- 2024
- Variant of
- Updated
DimensionsAs issued, without a magazine or an optic.
- Barrel
- 262 mm
- Overall length
- 679 mm
- Weight, empty
- 2.60 kg
ActionHow it cycles, what trips it, and what feeds it.
- Action
- Gas operated direct impingement
- Firing mechanism
- Hammer fired
- Trigger
- Single stage
- Capacity
- 30
- Magazine
- Detachable box
MaterialsEach swatch is the material itself, not a colour chosen to stand for it.
- Frame
- Aluminum
- 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.
Cold hammer forged barrel
Chrome lined barrel
Free floating handguard
Grip n rip charging handle
M4 feed ramps
Flat top receiver
Picatinny rail
Ris iii handguard
M lok attachment
Carbine length gas system
Adjustable stock
Fully ambidextrous lower
H buffer
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 141 5.56x45mm NATO carbines | 2.60 kg | 2.95 kg | Lighter than about 90% |
| Overall lengthAmong 144 5.56x45mm NATO carbines | 679 mm | 838 mm | Shorter than about 90% |
| Barrel lengthAmong 150 5.56x45mm NATO carbines | 262 mm | 406 mm | Shorter than about 90% |
| Magazine capacityAmong 150 5.56x45mm NATO carbines | 30 | 30 | Near the median |
Answers
Questions about the Daniel Defense MK18 RIII
How much does the Daniel Defense MK18 RIII weigh?
The Daniel Defense MK18 RIII weighs 2.60 kg (5.73 lb) empty.
What caliber is the Daniel Defense MK18 RIII?
The Daniel Defense MK18 RIII is chambered in 5.56x45mm NATO.
How many rounds does the Daniel Defense MK18 RIII hold?
The Daniel Defense MK18 RIII holds 30 rounds, fed from a detachable box magazine.
How long is the Daniel Defense MK18 RIII?
The Daniel Defense MK18 RIII is 679 mm (26.7 in) long overall, with a 262 mm (10.31 in) barrel.
Who makes the Daniel Defense MK18 RIII?
The Daniel Defense MK18 RIII is made by Daniel Defense (United States).
When was the Daniel Defense MK18 RIII introduced?
The Daniel Defense MK18 RIII was introduced in 2024.
How does the Daniel Defense MK18 RIII operate?
The Daniel Defense MK18 RIII uses a gas operated direct impingement 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
85%
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/daniel-defense-mk18-riii' \ --header 'X-API-Key: your_key'{ "id": "daniel-defense-mk18-riii", "name": "Daniel Defense MK18 RIII", "manufacturer": { "id": "daniel-defense", "name": "Daniel Defense", "countryCode": "US", "foundedYear": 2000, "website": "https://www.danieldefense.com", "logoUrl": null, "description": null, "status": null, "defunctYear": null, "stateOwned": null, "makesFirearms": null, "parentId": null, "predecessorId": null, "createdAt": "2026-02-11 23:44:38", "updatedAt": "2026-02-18 03:43:46", "version": "6d10d3d98b28a078568620c53754ace8fc3c89156db0b437cd09a8e82678df77" }, "category": { "id": "carbine", "name": "Carbine", "description": "Shortened rifles for close-quarters use" }, "country_of_origin": "US", "year_introduced": 2024, "barrel_length_mm": 262, "weight_empty_g": 2599, "action_type": "gas_operated_direct_impingement"}