The Colt M4 Carbine Monolithic Rifle 5.56 NATO 16.1 in. Matte Black 30 rd. is the LE6940 model, a gas-operated carbine built for ranch and utility work where you need to hang a sight, a light, and a foregrip without playing Tetris with your rail space. This rifle uses a patented one-piece monolithic upper receiver with a continuous Mil-Spec rail from the rear of the upper to the front sight, giving you four full rail positions for mounting accessories. It comes with an MBUS rear sight and a Colt folding front sight, so you can run optics and still have backup irons. Per Colt specs, this is the rifle you want when you need to mount multiple devices—optics, lasers, lights, foregrips—and have endless mounting options without losing zero.
| Manufacturer | Colt |
|---|---|
| Model | LE6940 |
| Material | 7075-T6 aluminum upper receiver, carbon steel barrel (per manufacturer specs) |
| Compatibility | Standard AR-15 lower receivers, Mil-Spec buffer tubes |
| Finish | Matte black hardcoat anodized |
| Weight | 7.5 lbs (unloaded, per manufacturer specs) |
| Condition | New |
Key Features
- Monolithic Upper Receiver – WHY IT MATTERS: One-piece construction from the receiver to the front sight means your rail stays rigid under heavy loads, so optics, lasers, and lights hold zero even after a day of bouncing around in a truck rack or side-by-side.
- Continuous Mil-Spec Rail – WHY IT MATTERS: Four full rail positions give you room to mount a red dot, a magnifier, a weapon light, and a foregrip without stacking adapters or losing real estate. You can set it up for coyote hunting at dawn and still have a light for predator control at dusk.
- MBUS Rear Sight and Colt Folding Front Sight – WHY IT MATTERS: Backup irons are already on the gun, so you don’t have to buy extra sights. The folding front sight clears your optic window, and the MBUS rear flips up when your battery dies or your glass gets fogged—no tools needed.
- Gas-Operated Direct Impingement System – WHY IT MATTERS: Proven reliability with a 16.1-inch chrome-lined barrel that cycles 5.56 NATO and .223 Remington ammunition without hiccups. It’s the same system used by law enforcement and military units that need a rifle that runs dirty and keeps going.
- 30-Round Magazine Capacity – WHY IT MATTERS: You get a full magazine from the factory, so you can load up for predator control, range practice, or ranch security without hunting down extra mags. The standard AR-15 magazine interface means you can use any 30-round or 20-round mag you already own.
Who It’s For
This rifle is for ranchers, rural workers, and utility buyers who need a tool that mounts lights, lasers, and optics without compromise. If you’re running night vision for hog control, hanging a thermal scope for coyote management, or just want a carbine that can take a beating on a four-wheeler and still shoot sub-2 MOA, the LE6940 is built for that life. It’s not a safe queen—it’s a working rifle.
Pros and Cons
- Pros: Monolithic rail is rock-solid; backup sights included; 16.1-inch barrel balances maneuverability and velocity; Mil-Spec reliability from Colt; four rail positions give you room for multiple accessories.
- Cons: The monolithic upper means you can’t swap handguards easily—if you want a different rail system, you’re buying a new upper. Also, the weight is slightly heavier than some free-float carbines due to the one-piece construction, but that rigidity is worth the trade-off for heavy accessory loads.
Comparison
| Feature | Colt LE6940 | Geissele Super Duty 16” | Zev Technologies OZ-9C (Pistol) |
|---|---|---|---|
| Receiver Type | Monolithic one-piece upper | Standard upper with free-float rail | Modular handgun frame (not comparable) |
| Barrel Length | 16.1 inches | 16 inches | 4.5 inches |
| Weight | 7.5 lbs | 6.8 lbs | 1.8 lbs |
| Rail Mounting | Continuous Mil-Spec, 4 positions | Free-float M-LOK, 4 positions | Picatinny top rail, 2 positions |
| Price | $1526.71 | ~$1800 | ~$1500 |
| Best For | Heavy accessory loads, ranch work | Lightweight patrol carbine | Concealed carry, competition |
The Colt LE6940 is in a different category than the Geissele Super Duty—both are top-tier carbines, but the Colt’s monolithic rail is better for hanging multiple devices without flex. The Zev OZ-9C is a pistol, included here to show that if you need a long gun for utility work, the Colt is the right tool.
FAQ
What caliber does the Colt M4 Carbine Monolithic Rifle shoot?
It shoots 5.56 NATO and .223 Remington. The 16.1-inch chrome-lined barrel is rated for both, so you can use commercial .223 for plinking and 5.56 for duty or predator loads.
Does this rifle come with sights?
Yes, it includes an MBUS rear sight and a Colt folding front sight. The front sight folds down to clear your optic, and the rear flips up when needed. You don’t have to buy extra irons.
Can I mount a suppressor on this rifle?
The barrel is 16.1 inches with a standard A2 flash hider (1/2×28 threads). You can remove the flash hider and mount a suppressor, but the monolithic handguard may require a low-profile gas block if the suppressor doesn’t clear the rail. Check your suppressor’s diameter before mounting.
What magazines does this rifle use?
It takes standard AR-15/M16 magazines. The rifle comes with one 30-round magazine, but you can use any 20-round or 30-round mag from brands like Magpul, Lancer, or Colt.
Is this rifle legal in all states?
This is a 16.1-inch barreled rifle with a standard stock, so it’s legal in most states that allow semi-auto rifles. Check your local laws for magazine capacity restrictions—some states limit to 10 rounds.
✔ Nationwide delivery (all 50 states) | ✔ Ships 1-2 business days | ✔ 30-day returns | ✔ Secure checkout
Browse more Semi Auto Rifles or check our AR-15 Uppers and Optics & Sights for your build.
Last updated: April 2026
FFL Transfer & Firearms Laws for Colt M4 Carbine Monolithic Rifle 5.56 Nato 16.1 in. Matte Black 30 rd.
All firearms, including the Colt M4 Carbine Monolithic Rifle 5.56 Nato 16.1 in. Matte Black 30 rd., must be shipped to a licensed Federal Firearms License (FFL) dealer. You will be required to complete a background check and any necessary paperwork before taking possession.
How It Works
- Place your order online.
- Provide your preferred FFL dealer information.
- We ship the firearm directly to your FFL.
- You complete the background check and pickup at the FFL.
Legal Compliance
We comply with all federal and state firearm laws. It is your responsibility to ensure the Colt M4 Carbine Monolithic Rifle 5.56 Nato 16.1 in. Matte Black 30 rd. is legal in your state. Some states may have restrictions on certain firearm models or features.
Helpful Resources
Need assistance? Contact our Miami store for help with FFL transfers and firearm compliance.
Frequently Asked Questions About This Product
Why buy Colt M4 Carbine Monolithic Rifle 5.56 Nato 16.1 in. Matte Black 30 rd. from Miami Shooters Supply?
We’re a trusted firearms dealer offering fast shipping, competitive pricing, and 100% compliance with U.S. federal firearm laws. All orders ship from our licensed facility with full tracking and expert customer service.
Where can I buy Colt M4 Carbine Monolithic Rifle 5.56 Nato 16.1 in. Matte Black 30 rd.?
You can purchase this item directly on our website and have it shipped to your local FFL dealer. You can also visit us in-store in Miami, Florida.
Is Colt M4 Carbine Monolithic Rifle 5.56 Nato 16.1 in. Matte Black 30 rd. available now?
Availability is shown live on this page. If the “Add to Cart” button is visible, this item is currently in stock and ready to ship.
What category does this product belong to?
This product is listed under: Semi Auto Rifles.
What tags or features does this product have?
Key features and tags for this product include: .
Is this product legal in my state?
It is your responsibility to ensure this item is legal in your state or locality. We ship only to valid FFL dealers in compliance with U.S. laws. Always check your local regulations.





Reviews
There are no reviews yet.