Colt CR6940 / LE6940 Monolithic Carbine

Colt monolithic-upper carbine with a one-piece 7075-T6 upper receiver, continuous integral top Picatinny rail, 16.1-inch chrome-lined M4-profile barrel, folding front sight, and direct-gas operating system.

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Key Highlights

•Colt monolithic one-piece upper with continuous top rail from receiver to gas block
•16.1" chrome-lined M4-profile barrel, 1:7 twist, 1/2x28 threads
•Integral folding front sight on the monolithic rail

Specifications

Price: $1,399
Weight: 7 lb 1 oz
Calibers: 5.56x45mm, .223 Rem
Rail Type: picatinny
Best For: duty patrol home defense outdoor defense

Capability Profile

0-10 Scale Across 8 Axes

Compatibility Tags

family: modern-riflefamily: ar-patterntrigger: ar-fcginterface: picatinny-topbarrel: longthread: 1/2x28mag-type: stanag

Overview

The Colt CR6940 / LE6940 Monolithic Carbine is Colt's monolithic-upper AR carbine. Its defining feature is a one-piece 7075-T6 aluminum upper receiver that machines the flat-top and the free-floating handguard into a single part, so the top Picatinny rail runs unbroken from the charging handle to the gas block. That continuous rail holds zero across optic removal and reinstallation better than a two-piece flat-top-plus-handguard setup, and it keeps backup irons, magnifiers, and night vision devices on the same plane with no rail gap at the receiver joint. The gas system is direct impingement; the piston-driven version is the separate LE6940P.

Key Features

One-piece 7075-T6 monolithic upper receiver with integral free-float handguard
Continuous MIL-STD-1913 top rail from receiver to gas block
16.1" chrome-lined M4-profile barrel, 1:7 twist, 1/2x28 threads
Carbine-length direct impingement gas system (LE6940P is the piston variant)
Folding front sight integrated into the gas block
A2 birdcage flash hider, four-position collapsible stock, A2 grip
30-round STANAG magazine compatibility

Pros

+Monolithic one-piece upper keeps the top rail true to bore and holds optic zero across removal
+Continuous rail co-planes optics, magnifiers, backup irons, and IR lasers with no receiver gap
+Chrome-lined 16.1" M4-profile barrel with 1:7 twist stabilizes 55 to 77 grain 5.56
+Integral folding front sight ships usable and stows flat under an optic
+Threaded 1/2x28 muzzle accepts standard 5.56 muzzle devices and suppressor mounts
+Full-length side and bottom rails mount lights and lasers directly

Cons

−Heavier at about 7 lbs than modern free-float M-LOK carbines like the BCM RECCE-16
−Quad-rail monolith needs rail covers and is not as slim or light as an M-LOK forend
−Proprietary one-piece upper is not a host for aftermarket free-float handguards
−Mil-spec single-stage trigger breaks heavy, near 7 lbs from the factory
−Collapsible stock can exhibit some wobble on the buffer tube
−Legacy design with limited new-production availability versus current M-LOK carbines