CMMG Banshee
- Category
- Carbine
- Barrel
- 127 mm
- Weight, empty
- 2.18 kg
- Introduced
- 2017
About
What it is, and why it matters
The CMMG Banshee is a compact AR-15 pattern pistol-caliber carbine featuring CMMG's innovative Radial Delayed Blowback (RDB) operating system. Introduced in 2017, the Banshee is available in multiple calibers including 9mm, .45 ACP, 10mm, 5.7x28mm, and .300 Blackout, with barrel lengths ranging from 5 to 8 inches depending on variant. The RDB system uses a radial cam system to delay bolt unlocking, allowing lighter bolt weights and reduced recoil compared to traditional straight blowback PCCs while maintaining reliability. The 9mm variant weighs just 4.8 pounds and features a 5-inch medium-taper threaded barrel machined from 4140 chrome-moly steel. The Banshee includes CMMG's ZEROED line of enhanced components including an ambidextrous charging handle, ambidextrous safety selector, single-stage trigger, and oversized bolt catch. The free-floating M-LOK handguard provides mounting options for accessories while the aircraft-grade aluminum receivers ensure durability. The compact design makes the Banshee ideal for personal defense, vehicle operations, and close-quarters applications.
CMMG developed the Radial Delayed Blowback system to address the shortcomings of direct blowback pistol-caliber carbines. The company's founders, Jeff Overstreet, John, Gretchen, and Stephanie Crabtree, wanted to create a PCC that offered AR-15 ergonomics with pistol-caliber ammunition efficiency. The Banshee name reflects the weapon's compact, aggressive profile. The platform has become popular in competitive shooting, particularly 3-Gun and PCC divisions, where its light weight and soft recoil provide competitive advantages.
CMMG's Radial Delayed Blowback system represents a significant innovation in pistol-caliber carbine design. Traditional blowback PCCs require heavy bolts to delay opening long enough for pressure to drop safely, resulting in harsh recoil and limited cyclic rates. The RDB system uses angled lugs on the bolt that engage corresponding cuts in the barrel extension, forcing the bolt to rotate during rearward travel. This rotation delays unlocking just long enough for safe pressure reduction while allowing a much lighter bolt - the RDB bolt weighs significantly less than comparable straight blowback designs. The result is softer recoil, faster cycling, and improved reliability. The Banshee platform is available as both pistols (with arm braces) and SBRs (with stocks). CMMG manufactures the Banshee in Boonville, Missouri, and the platform has gained popularity in competitive shooting disciplines like PCC division.
Specification
Everything measured
IdentityWhat it is, who built it and when.
- Manufacturer
- CMMG Inc.
- Category
- Carbine
- Country
- United States
- Status
- In production
- Produced
- 2017
DimensionsAs issued, without a magazine or an optic.
- Barrel
- 127 mm
- Overall length
- 533 mm
- Height
- 133 mm
- Width
- 32 mm
- Weight, empty
- 2.18 kg
- Weight, loaded
- 2.50 kg
ActionHow it cycles, what trips it, and what feeds it.
- Action
- Delayed blowback
- Firing mechanism
- Hammer fired
- Trigger
- Single stage
- Trigger pull
- 22.0 N
- Capacity
- 30
- 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
- 380 m/s
- Muzzle energy
- 537 J
- Effective range
- 100 m
- Maximum range
- 1800 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
Ar15 pattern
Last round bolt hold open
Ambidextrous controls
M lok handguard
Threaded barrel
Picatinny rail
Compact design
Free floating handguard
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 | 2.18 kg | 2.78 kg | Lighter than about 90% |
| Overall lengthAmong 56 9x19mm Parabellum carbines | 533 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 | 30 | 24 | Holds more rounds than about 70% |
Answers
Questions about the CMMG Banshee
How much does the CMMG Banshee weigh?
The CMMG Banshee weighs 2.18 kg (4.80 lb) empty and 2.50 kg (5.51 lb) loaded.
What caliber is the CMMG Banshee?
The CMMG Banshee is chambered in 9x19mm Parabellum.
How many rounds does the CMMG Banshee hold?
The CMMG Banshee holds 30 rounds, fed from a detachable box magazine.
How long is the CMMG Banshee?
The CMMG Banshee is 533 mm (21.0 in) long overall, with a 127 mm (5.00 in) barrel.
Who makes the CMMG Banshee?
The CMMG Banshee is made by CMMG Inc. (United States).
When was the CMMG Banshee introduced?
The CMMG Banshee was introduced in 2017.
How does the CMMG Banshee operate?
The CMMG Banshee 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
88%
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' \ --header 'X-API-Key: your_key'{ "id": "cmmg-banshee", "name": "CMMG Banshee", "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": 2017, "barrel_length_mm": 127, "weight_empty_g": 2177, "action_type": "delayed_blowback"}