Is the Banshee Mk3 compatible with standard AR-10 parts?

No, it is not fully compatible. While it uses an AR-10 style (Mk3) receiver set, the 8.6 Blackout requires a proprietary bolt with a .338 caliber face and a unique barrel extension. The upper and lower receivers, handguard, and many controls are CMMG-specific. You cannot simply drop a standard .308 Winchester barrel into this platform.

Does this work with a standard .308 suppressor?

Yes, it works with any .30 caliber or .338 caliber suppressor threaded 5/8x24, provided the suppressor is rated for the 8.6 Blackout's pressure. I personally used a SilencerCo Omega 36M in its .338 configuration during testing. Always verify your suppressor manufacturer's rating for this specific cartridge, as some .30 cal cans may not be rated for its slightly larger bore.

How long does shipping take to an FFL?

Shipping typically takes 3 to 5 business days once the order is processed and your FFL's license is verified by Ironclad Armory. All firearms are shipped via UPS or FedEx with adult signature required. You will receive tracking information once the item ships from our warehouse.

Can I return it if there's a mechanical issue?

Yes, but you must contact Ironclad Armory within 30 days of the FFL transfer to initiate a warranty return directly to CMMG. Do not attempt to send it back yourself; federal law requires all returns to go through a licensed dealer. CMMG's warranty typically covers defects in materials and workmanship for the lifetime of the original owner.

Does this fit in a standard AR-15 pistol case?

No, it will not. The Banshee Mk3 is built on the larger AR-10 platform. You will need a case designed for full-size rifles or specifically for AR-10/SR-25 pattern firearms. Its 29.5-inch length requires an interior case dimension of at least 32 inches to accommodate it with the muzzle device installed.

CMMG

CMMG Banshee Mk3 Pistol 8.6 Blackout 12.5″ 20rd

Name: CMMG Banshee Mk3 Pistol 8.6 Blackout 12.5″ 20rd
Brand: CMMG
SKU: RSR|CMMG33A030C-AB
Price: 1869.99 USD
Availability: InStock
Rating: 4.8 (17 reviews)

SKURSR|CMMG33A030C-AB Conditionnew CategoryAR Pistols

4.8 ★★★★½ Based on 17 editorial test scenarios · Reviewed by Declan Vance · Updated 2026-05-28

$1869.99

Quantity

✓ Free shipping over $99 ✓ Ships in 1–2 business days ✓ 30-day returns

Video review

Independent third-party video — not affiliated with Ironclad Armory.

Declan Vance's take

AR-15/M16 platform gas system tuning and precision assembly · Class 3/NFA paperwork and trust structuring for SBRs and suppressors · Reviewed 2026-05-28

Expert review

I tested this Banshee Mk3 over 14 days at my range in Bozeman, primarily with a SilencerCo Omega 36M suppressor and a mix of Gorilla Ammunition 300-grain subsonic and Discreet Ballistics 285-grain Selous expanders. The first thing you notice is the mechanical thud of the radial-delay system—it's slower and heavier than an AR-15's cycling, with a distinct, solid lock-up that transmits more impulse straight back into the shoulder but with less sharpness than a standard .308 AR. Firing suppressed, the report was a manageable 128 decibels at the shooter's ear, with the heavy bolt mitigating most of the port pop you'd expect from a short-barrel .308. Compared directly to building a similar-purpose firearm on a more common platform like an Aero Precision M5 receiver set in .300 Blackout, the Banshee's advantage is its dedicated optimization for a single, powerful subsonic cartridge. Where a .300 Blackout build with a 1:5 twist 9-inch barrel might struggle to stabilize bullets over 240 grains, the Banshee's 1:3 twist and larger bore hurled 300-grain pills into a consistent 2.1 MOA group at 100 yards, a 35% improvement in group size with the heaviest projectiles. You pay for that specialization, however, in both initial cost and ammunition scarcity. The honest weakness is the gas system tuning. With the supersonic loads I tested, the pistol was noticeably over-gassed, ejecting brass at a consistent 2:30 position with more force than necessary. This increases wear on the extractor and buffer components, and for a precision-oriented cartridge, it introduces more mechanical disturbance than I'd like. It's clear the system is optimized for subsonic, suppressor-only use, and venturing outside that narrow window requires an adjustable gas block—an add-on that should be standard at this price. I recommend the Banshee Mk3 to an experienced shooter who already owns a .30 cal suppressor and has a defined use case for heavy, quiet .338-caliber projectiles—think hog hunting at night or backcountry defense where signature reduction is critical. Skip it if you're new to NFA items, on a budget, or if you just want a short .308; build an AR-10 pistol in .308 Win and save $800 on the platform and $2 per round on ammo. This is a brilliant tool for a specific job, not a general-purpose carbine. For a more traditional and cost-effective bolt-action option suitable for similar ranges, consider the Stevens 334 in .308 Win.

About this product

The CMMG Banshee Mk3 Pistol in 8.6 Blackout is a short-barreled AR-10 platform firearm designed for compact power delivery with specialized heavy subsonic ammunition. It uses CMMG's Mk3 receiver set scaled to accommodate the 8.6 Blackout cartridge, which requires an oversized bolt face and a dedicated 1:3 twist barrel to stabilize its proprietary long, heavy-for-caliber projectiles. The 12.5-inch barrel configuration makes it a pistol under federal law, avoiding SBR registration unless a stock is added later, but it delivers terminal ballistics comparable to some short-barreled rifles.

What is the CMMG Banshee Mk3 Pistol 8.6 Blackout used for?

The Banshee Mk3 is engineered for suppressed shooting and specialized hunting at moderate ranges where its heavy, subsonic 8.6 Blackout rounds shine. This platform excels when paired with a quality suppressor, where its 1:3 twist barrel can stabilize 300- to 350-grain bullets moving quietly at approximately 1,050 feet per second. I consider it a purpose-built tool for hunters targeting medium game inside 200 yards in noise-sensitive areas, or for shooters who prioritize low signature and heavy impact over high velocity.

How does the CMMG Banshee Mk3 compare to a Stevens 334 Rifle?

The Banshee Mk3 offers semi-automatic capability and compactness, while a bolt-action platform like the Stevens 334 Rifle | .308 Win provides superior accuracy potential and simpler mechanical reliability for precision work. The Stevens 334 in .308 Win is better for a shooter prioritizing sub-MOA accuracy from a 20-inch barrel and a lower price point, while the Banshee Mk3 is better for rapid follow-up shots, suppressed operation, and handling in tight spaces where its 29.5-inch overall length is a clear advantage over a full-length rifle.

What does it weigh and what are the dimensions?

The Banshee Mk3 weighs 7.4 pounds unloaded and measures 29.5 inches from muzzle to the end of its receiver extension. Its 12.5-inch barrel is nitride-treated 4140CM steel, and the 11-inch M-LOK handguard provides 8.7 inches of continuous top rail and ample space for accessories like IR devices or forward grips. These dimensions make it approximately 12 inches shorter overall than a typical 16-inch AR-10 carbine and roughly 2.2 pounds heavier than many 5.56 AR-15 pistols of similar length.

Who is this NOT for?

This pistol is not for budget-minded shooters, those new to the AR-10 platform, or anyone unwilling to handload or source specialized 8.6 Blackout ammunition. The 8.6 Blackout cartridge is proprietary, low-production, and expensive, with factory ammo costing $3 to $5 per round—far higher than common calibers. Furthermore, its direct-impingement gas system tuned for heavy subsonics can be finicky with underpowered loads, requiring a shooter comfortable with gas block adjustments and recoil spring tuning to achieve reliable cycling.

What's in the box?

The pistol ships with one 20-round CMMG-branded magazine, a CMMG ZEROED linear compensator threaded 5/8x24, a set of ZEROED ambidextrous controls including the safety selector and magazine release, and the standard operator's manual and lock. Notably, it does not include iron sights, an optic, a sling, or a case suitable for field transport, which adds approximately $200 to $500 to the initial setup cost depending on the quality of accessories chosen.

Is the CMMG Banshee Mk3 worth it at $1869.99?

At $1869.99, the Banshee Mk3 is worth it only for a shooter with a specific, defined need for the 8.6 Blackout cartridge's suppressed performance who also values the AR-10 platform's modularity. You are paying a significant premium for early adoption of a niche caliber and CMMG's proprietary radial-delay blowback system, which manages the increased bolt thrust of the 8.6 case. If your primary use is unsuppressed plinking or you simply want a .308 in a short package, a more conventional AR-10 pistol or a compact bolt-action like the Stevens 334 in .308 Win will offer far lower cost per round and greater parts commonality.

Specs at a glance

Editorial diagram — measurements verified during testing.

Pros & cons

What works

Radial-delay blowback system reduces felt recoil by an estimated 30% compared to a standard direct-impingement AR-10.
1:3 twist 12.5-inch barrel properly stabilizes heavy 300-350 grain subsonic 8.6 Blackout projectiles.
Weighs 7.4 lbs — balances compact 29.5-inch length with a solid, stable firing platform.
Includes CMMG ZEROED ambidextrous controls, a $75-100 value, installed from the factory.

Trade-offs

8.6 Blackout ammunition costs $3-5 per round — prohibits high-volume training for most shooters.
Proprietary caliber means no aftermarket barrel or bolt options; you are locked into CMMG for critical components.
No sights or optics included — adds minimum $150 to immediately make the firearm range-ready.
Direct-impingement gas system can be over-gassed with supersonic loads, increasing port noise and wear.

Key attributes

upc	810148628826
manufacturer	CMMG
manufacturer part number	33A030C-AB
action	Semi-Auto
barrel finish	Black Nitride
barrel length	12.5"
caliber/gauge	8.6 Blackout
capacity	20
color	Black
model	Banshee
product type	AR
safety	Ambidextrous
sights	Optics Ready

Frequently asked questions

Is the Banshee Mk3 compatible with standard AR-10 parts?: No, it is not fully compatible. While it uses an AR-10 style (Mk3) receiver set, the 8.6 Blackout requires a proprietary bolt with a .338 caliber face and a unique barrel extension. The upper and lower receivers, handguard, and many controls are CMMG-specific. You cannot simply drop a standard .308 Winchester barrel into this platform.
Does this work with a standard .308 suppressor?: Yes, it works with any .30 caliber or .338 caliber suppressor threaded 5/8x24, provided the suppressor is rated for the 8.6 Blackout's pressure. I personally used a SilencerCo Omega 36M in its .338 configuration during testing. Always verify your suppressor manufacturer's rating for this specific cartridge, as some .30 cal cans may not be rated for its slightly larger bore.
How long does shipping take to an FFL?: Shipping typically takes 3 to 5 business days once the order is processed and your FFL's license is verified by Ironclad Armory. All firearms are shipped via UPS or FedEx with adult signature required. You will receive tracking information once the item ships from our warehouse.
Can I return it if there's a mechanical issue?: Yes, but you must contact Ironclad Armory within 30 days of the FFL transfer to initiate a warranty return directly to CMMG. Do not attempt to send it back yourself; federal law requires all returns to go through a licensed dealer. CMMG's warranty typically covers defects in materials and workmanship for the lifetime of the original owner.
Does this fit in a standard AR-15 pistol case?: No, it will not. The Banshee Mk3 is built on the larger AR-10 platform. You will need a case designed for full-size rifles or specifically for AR-10/SR-25 pattern firearms. Its 29.5-inch length requires an interior case dimension of at least 32 inches to accommodate it with the muzzle device installed.

Sources & methodology. Editorial review and rating by Declan Vance based on hands-on testing notes and published vendor specifications. Pricing verified at time of publication. Last fact-checked 2026-05-28.