CMMG Resolute Mk57
- Category
- Carbine
- Barrel
- 409 mm
- Weight, empty
- 2.81 kg
- Introduced
- 2019
About
What it is, and why it matters
The CMMG Resolute Mk57 is a carbine-length AR-pattern rifle chambered in the high-velocity 5.7x28mm cartridge, sharing the full-size Resolute chassis with a 16.1-inch barrel. Unlike traditional AR-15 calibers, the Mk57 uses CMMG's Radial Delayed Blowback (RDB) operating system to safely cycle the bottleneck 5.7x28 round without a gas system, allowing a lighter, simpler action. The Mk57 feeds from proprietary CMMG/ProMag 5.7x28mm magazines (20-round standard) and offers flat-shooting, low-recoil performance with excellent short-range penetration. The rifle ships with CMMG's ZEROED components - ambidextrous charging handle, ambidextrous safety, and single-stage trigger - on aircraft-grade aluminum receivers with a Cerakote finish and M-LOK free-float handguard. At only 6.2 pounds, the Resolute Mk57 is a lightweight, soft-shooting carbine well-suited to recreational shooting and home defense.
CMMG was among the first manufacturers to chamber the FN-developed 5.7x28mm cartridge in an AR-pattern platform for the civilian market, applying its Radial Delayed Blowback technology to tame the bottleneck round without a gas system.
MSRP approximately $1,799. The Resolute Mk57 is the 16.1"-barreled carbine sibling of the compact Banshee Mk57 (already catalogued separately). Both share the 5.7x28mm chambering and Radial Delayed Blowback action but differ substantially in barrel length and overall size.
Specification
Everything measured
IdentityWhat it is, who built it and when.
- Manufacturer
- CMMG Inc.
- Category
- Carbine
- Country
- United States
- Status
- In production
- Produced
- 2019
DimensionsAs issued, without a magazine or an optic.
- Barrel
- 409 mm
- Overall length
- 826 mm
- Weight, empty
- 2.81 kg
- Weight, loaded
- 2.87 kg
ActionHow it cycles, what trips it, and what feeds it.
- Action
- Delayed blowback
- Firing mechanism
- Hammer fired
- Trigger
- Single stage
- Trigger pull
- 28.0 N
- Capacity
- 20
- 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
- Cerakote
BallisticsFrom the service cartridge, not a handload.
- Muzzle velocity
- 716 m/s
- Muzzle energy
- 534 J
- Effective range
- 200 m
- Maximum range
- 1500 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.
M lok handguard
Free floating handguard
Ambidextrous controls
Ar15 pattern
Picatinny rail
Threaded barrel
Collapsible stock
Single stage trigger
Muzzle brake
Radial delayed blowback
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 409 carbines | 2.81 kg | 3.00 kg | Lighter than about 70% |
| Overall lengthAmong 407 carbines | 826 mm | 895 mm | Shorter than about 70% |
| Barrel lengthAmong 423 carbines | 409 mm | 406 mm | Near the median |
| Magazine capacityAmong 423 carbines | 20 | 21 | Near the median |
Answers
Questions about the CMMG Resolute Mk57
How much does the CMMG Resolute Mk57 weigh?
The CMMG Resolute Mk57 weighs 2.81 kg (6.20 lb) empty and 2.87 kg (6.34 lb) loaded.
What caliber is the CMMG Resolute Mk57?
The CMMG Resolute Mk57 is chambered in 5.7x28mm FN.
How many rounds does the CMMG Resolute Mk57 hold?
The CMMG Resolute Mk57 holds 20 rounds, fed from a detachable box magazine.
How long is the CMMG Resolute Mk57?
The CMMG Resolute Mk57 is 826 mm (32.5 in) long overall, with a 409 mm (16.1 in) barrel.
Who makes the CMMG Resolute Mk57?
The CMMG Resolute Mk57 is made by CMMG Inc. (United States).
When was the CMMG Resolute Mk57 introduced?
The CMMG Resolute Mk57 was introduced in 2019.
How does the CMMG Resolute Mk57 operate?
The CMMG Resolute Mk57 uses a delayed blowback 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
81%
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/cmmg-resolute-mk57' \ --header 'X-API-Key: your_key'{ "id": "cmmg-resolute-mk57", "name": "CMMG Resolute Mk57", "manufacturer": { "id": "cmmg", "name": "CMMG Inc.", "countryCode": "US", "foundedYear": 2002, "website": "https://cmmg.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 03:43:43", "version": "a7e68de40df3e6e52ce7309f32c551e46f69ca644a4955a2de5291d2bfbf7a0b" }, "category": { "id": "carbine", "name": "Carbine", "description": "Shortened rifles for close-quarters use" }, "country_of_origin": "US", "year_introduced": 2019, "barrel_length_mm": 409, "weight_empty_g": 2812, "action_type": "delayed_blowback"}