
Availability: In Stock
The Colt M4 LE6943 upper receiver group with 11.5-inch barrel is a complete, ready-to-assemble upper designed for shooters building or upgrading a modern tactical or patrol rifle. This upper comes fully spec'd with a bolt carrier group and integrated flip-up sights, so you can mount it to a compatible lower receiver and get on target without additional major component purchases. The 11.5-inch barrel length strikes a practical balance for close-quarters work, vehicle use, and confined spaces while maintaining the reliability Colt is known for in law enforcement and military platforms.
The monolithic upper receiver design is the standout here—Colt machined this as a single-piece platform with an integrated Picatinny rail running the full length of the top. That one-piece construction delivers superior rigidity and consistent optics mounting compared to traditional split-rail uppers, and the unified structure eliminates the flex and tolerance stack that can accumulate where separate rail sections meet. The barrel is completely free-floated, meaning it hangs freely in the receiver without contact to the handguard, which promotes accuracy by removing unwanted vibration during firing. Your shots won't be thrown off by pressure points or inconsistent barrel harmonics.
The barrel itself is chrome-lined 4150 steel with a 1-to-7 twist rate and button-rifled finish—a proven combination that handles all common 5.56 NATO and .223 Remington loads, including heavier match and barrier-penetrating rounds. Chrome lining adds durability and corrosion resistance in harsh conditions, a feature you'll appreciate if you're running this upper hard or in dusty, wet, or salt-air environments. The included flip-up front sight is compatible with standard-height rear sight systems, so you have a zero backup if your optic goes down.
Because this upper arrives complete with bolt carrier group and sights, you're not left hunting for parts—just pair it to a stripped lower receiver, add furniture and trigger as desired, and you have a functional rifle. This is ideal if you're a builder looking to skip the research and parts sourcing, or if you want a quality complete upper ready to go into a build without guesswork.
| Brand | Colt |
| Model | LE6943 |
| Barrel Length | 11.5 inches |
| Barrel Material | Chrome-lined 4150 steel |
| Twist Rate | 1-to-7 |
| Rifling Type | Button rifled |
| Upper Receiver Type | Monolithic |
| Includes | Bolt carrier group and flip-up front sight |
| Compatible Ammunition | 5.56 NATO, .223 Remington |
| Rail System | Integrated Picatinny (top) |
The LE6943 upper includes the bolt carrier group and front sight, so you'll need a compatible stripped lower receiver. After that, you can add a stock, pistol grip, trigger group, and handguard or rail covers to suit your setup. The upper itself is ready to mount on a standard AR-15 lower.
Yes, the barrel is chrome-lined 4150 steel. Chrome lining adds a protective coating inside the bore that resists corrosion and extends barrel life, especially if you're shooting in wet, dusty, or high-salt environments, or if the rifle will see heavy use or long storage periods between cleanings.
A monolithic receiver is machined as one piece with the top rail integrated into it, eliminating the small gaps and flex points where separate rail sections would otherwise meet. This gives you a more rigid platform with better optics stability and more consistent, repeatable accuracy when mounting scopes or red dots.
The flip-up front sight is designed to be compatible with most standard-height rear sights. If you're using a co-witnessed or lower-third optics mount, confirm that your chosen rear sight height aligns with this front sight for proper zero reference.

SKU: 167528972 • Weight: 5oz





Availability: In Stock
The Colt M4 LE6943 upper receiver group with 11.5-inch barrel is a complete, ready-to-assemble upper designed for shooters building or upgrading a modern tactical or patrol rifle. This upper comes fully spec'd with a bolt carrier group and integrated flip-up sights, so you can mount it to a compatible lower receiver and get on target without additional major component purchases. The 11.5-inch barrel length strikes a practical balance for close-quarters work, vehicle use, and confined spaces while maintaining the reliability Colt is known for in law enforcement and military platforms.
The monolithic upper receiver design is the standout here—Colt machined this as a single-piece platform with an integrated Picatinny rail running the full length of the top. That one-piece construction delivers superior rigidity and consistent optics mounting compared to traditional split-rail uppers, and the unified structure eliminates the flex and tolerance stack that can accumulate where separate rail sections meet. The barrel is completely free-floated, meaning it hangs freely in the receiver without contact to the handguard, which promotes accuracy by removing unwanted vibration during firing. Your shots won't be thrown off by pressure points or inconsistent barrel harmonics.
The barrel itself is chrome-lined 4150 steel with a 1-to-7 twist rate and button-rifled finish—a proven combination that handles all common 5.56 NATO and .223 Remington loads, including heavier match and barrier-penetrating rounds. Chrome lining adds durability and corrosion resistance in harsh conditions, a feature you'll appreciate if you're running this upper hard or in dusty, wet, or salt-air environments. The included flip-up front sight is compatible with standard-height rear sight systems, so you have a zero backup if your optic goes down.
Because this upper arrives complete with bolt carrier group and sights, you're not left hunting for parts—just pair it to a stripped lower receiver, add furniture and trigger as desired, and you have a functional rifle. This is ideal if you're a builder looking to skip the research and parts sourcing, or if you want a quality complete upper ready to go into a build without guesswork.
| Brand | Colt |
| Model | LE6943 |
| Barrel Length | 11.5 inches |
| Barrel Material | Chrome-lined 4150 steel |
| Twist Rate | 1-to-7 |
| Rifling Type | Button rifled |
| Upper Receiver Type | Monolithic |
| Includes | Bolt carrier group and flip-up front sight |
| Compatible Ammunition | 5.56 NATO, .223 Remington |
| Rail System | Integrated Picatinny (top) |
The LE6943 upper includes the bolt carrier group and front sight, so you'll need a compatible stripped lower receiver. After that, you can add a stock, pistol grip, trigger group, and handguard or rail covers to suit your setup. The upper itself is ready to mount on a standard AR-15 lower.
Yes, the barrel is chrome-lined 4150 steel. Chrome lining adds a protective coating inside the bore that resists corrosion and extends barrel life, especially if you're shooting in wet, dusty, or high-salt environments, or if the rifle will see heavy use or long storage periods between cleanings.
A monolithic receiver is machined as one piece with the top rail integrated into it, eliminating the small gaps and flex points where separate rail sections would otherwise meet. This gives you a more rigid platform with better optics stability and more consistent, repeatable accuracy when mounting scopes or red dots.
The flip-up front sight is designed to be compatible with most standard-height rear sights. If you're using a co-witnessed or lower-third optics mount, confirm that your chosen rear sight height aligns with this front sight for proper zero reference.
SKU: 167528972 • Weight: 5oz
