CMMG Banshee Mk17
- Category
- Carbine
- Barrel
- 127 mm
- Weight, empty
- 2.04 kg
- Introduced
- 2021
About
What it is, and why it matters
The CMMG Banshee Mk17 is a compact 9mm pistol-caliber AR-platform firearm built around CMMG's Radial Delayed Blowback operating system, which reduces bolt weight and softens the recoil impulse compared with traditional straight blowback PCCs. The Mk17 designation indicates it feeds from SIG Sauer P320 pattern magazines, with a standard 21-round capacity. It pairs a 5-inch barrel with a ZEROED RBB muzzle brake, an EML4 M-LOK handguard, ambidextrous controls, and the CMMG RipBrace.
The Mk17 variant of the Banshee line is distinguished by its SIG P320 magazine compatibility, whereas other Banshee models feed from Glock or Colt-pattern magazines. Offered as a braced pistol and as an SBR.
Specification
Everything measured
IdentityWhat it is, who built it and when.
- Manufacturer
- CMMG Inc.
- Category
- Carbine
- Country
- United States
- Status
- In production
- Produced
- 2021
DimensionsAs issued, without a magazine or an optic.
- Barrel
- 127 mm
- Overall length
- 528 mm
- Weight, empty
- 2.04 kg
ActionHow it cycles, what trips it, and what feeds it.
- Action
- Delayed blowback
- Firing mechanism
- Hammer fired
- Trigger
- Single action
- Capacity
- 21
- Magazine
- Detachable box
MaterialsEach swatch is the material itself, not a colour chosen to stand for it.
- Frame
- Aluminum
- Barrel
- Steel
- Finish
- Cerakote
BallisticsFrom the service cartridge, not a handload.
- Effective range
- 100 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.
Radial delayed blowback
M lok handguard
Ambidextrous charging handle
Muzzle brake
Accessory rail
Uses sig p320 magazines- Ripbrace
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 62 9x19mm Parabellum carbines | 2.04 kg | 2.78 kg | Lighter than about 90% |
| Overall lengthAmong 56 9x19mm Parabellum carbines | 528 mm | 820 mm | Shorter than about 90% |
| Barrel lengthAmong 64 9x19mm Parabellum carbines | 127 mm | 406 mm | Among the shortest tenth |
| Magazine capacityAmong 64 9x19mm Parabellum carbines | 21 | 24 | Holds fewer rounds than about 60% |
Answers
Questions about the CMMG Banshee Mk17
How much does the CMMG Banshee Mk17 weigh?
The CMMG Banshee Mk17 weighs 2.04 kg (4.50 lb) empty.
What caliber is the CMMG Banshee Mk17?
The CMMG Banshee Mk17 is chambered in 9x19mm Parabellum.
How many rounds does the CMMG Banshee Mk17 hold?
The CMMG Banshee Mk17 holds 21 rounds, fed from a detachable box magazine.
How long is the CMMG Banshee Mk17?
The CMMG Banshee Mk17 is 528 mm (20.8 in) long overall, with a 127 mm (5.00 in) barrel.
Who makes the CMMG Banshee Mk17?
The CMMG Banshee Mk17 is made by CMMG Inc. (United States).
When was the CMMG Banshee Mk17 introduced?
The CMMG Banshee Mk17 was introduced in 2021.
How does the CMMG Banshee Mk17 operate?
The CMMG Banshee Mk17 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
82%
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-banshee-mk17' \ --header 'X-API-Key: your_key'{ "id": "cmmg-banshee-mk17", "name": "CMMG Banshee Mk17", "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": 2021, "barrel_length_mm": 127, "weight_empty_g": 2041, "action_type": "delayed_blowback"}