LE6920: Colt’s Law Enforcement Carbine

By Christopher R. Bartocci

Since the adoption of the Colt M4 in 1995, there has been a desire for a carbine that would be semiautomatic only and would incorporate the improvements that made the M4 as accurate and as reliable as it is. Many law enforcement agencies liked the concept of the M4 but did not want the liability of issuing officers selective fire (burst or auto) weapons. Given the climate of crime in these times and the easy availability of body armor, it is essential for police to have high power rifles so they may deal with any possible situation.

The LE6920

Colt introduced the LE6920 in 1998. This weapon is as close as one can get to the mil-spec M4 that is supplied to American forces. This carbine differs only in the barrel length, 16.1 inches instead of 14.5 inches, and the omission of the burst/auto fire control settings. The first 1,500 carbines were sold to Kiesler Police Supply.

The barrel is 16.1 inches long with the standard A2-style muzzle brake/compensator. The barrel has the mil-spec 1/7-inch twist chrome lined barrel, which has been proof tested with a 70,000-psi proof cartridge, and then magnetic particle inspected to insure the barrel is free from any stress fractures. The 16.1 inch barrel is the ideal carbine length for optimal performance with the wide variety of 5.56x45mm (.223 Rem) ammunition available. Although the 14.5-barrel is more convenient and compact, problems have been found with the bullet not having enough velocity to maximize the terminal performance of the bullet as well as a decrease in the maximum effective range. The barrel also has the M4-style step in the front of the front sight assembly for the attachment of an M203 grenade launcher for law enforcement use using tear gas, smoke and less than lethal ammunition. The front sight assembly is the M4 spec (marked F on the left side of the front sight assembly), which sits higher than the standard front sight assembly to properly align the sights with the higher rear sight caused by the flat top upper receiver. Attached to the barrel is the side mounted sling swivel that comes from the factory to the left side of the carbine but may be switched to the right.

The handguard on the LE6920 is the standard issue double heat shielded M4-type. These handguards more efficiently protect the shooters hand from the heat of the barrel. However, the standard carbine handguards may be installed as well as the plethora of available advanced rail systems such as the A.R.M.S., Inc. SIR (Selective Integrated Rail) System.

The upper receiver is a standard Colt M4 with the Mil-Std-1913 rail flat top upper receiver. This receiver has the extended feed ramps in both the receiver as well as the barrel extension, which increase reliability in feeding cycles of operation. The upper receiver comes standard with a detachable carrying handle, which has the fully adjustable A2-style rear sight assembly but can readily be fitted with any available back-up rear sight. With the Mil-Std-1913 rail, any variety of optics may be placed on the carbine. Law enforcement agencies have made extensive use of the reflex-type sight for the close quarters engagement they encounter most often. These will include the Aimpoint M68 Comp II reflex sight, the EOTech holographic sight and the Trijicon ACOG reflex sight.

The bolt used in the LE6920 carbine is the mil-spec M4 bolt, which is test fired with a 70,000 psi proof cartridge and then magnetic particle inspected for stress. The extractor has the M4 heavy black buffer with the much stronger extractor spring increasing extractor life and increasing extraction force and reliability.

As of February of 2005, all LE6920s will utilize the standard selective fire bolt carrier. This may certainly be looked upon as an enhancement. First of all, there is extra mass increasing reliability under adverse conditions. Secondly, the hammer and firing pin are protected and will not wear as fast. Over a period of time on the standard bolt carrier, the hammer notch on top of the hammer damages the head of the firing pin and there is visible wear on the bottom of the bolt carrier where the hammer contacts on the rearward stroke.

The lower receiver has the mil-spec four-position telescopic buttstock in the current configuration with the longer butt. The sling swivel is on the bottom. However, any of the array of after market stocks will fit in the buffer extension. The lower receiver utilizes Colt’s proprietary .170 inches oversize hammer and trigger pins, which prevent illegal conversion to full automatic.

The LE6921 and LE6921HB

The LE6921 differs from the LE6920 only in the use of the standard mil-spec M4 barrel. By having this 14.5-inch barrel, the carbine is subject to the National Firearms Act and must be registered as a short-barreled firearm. The LE6921HB differs in the fact it uses the heavy SOCOM barrel utilized on the M4A1 carbines. The LE6922

The only difference between the LE6922 and the LE6920 it that the rifling has been changed from 1 turn in 7 inches to the slower 1 turn in 9 inches.

Specialized Armament Warehouse’s Custom LE6920HB

This model only differs in the fact that it has a heavy barrel. Basically, this is a 16.1 inch version of the heavy SOCOM barrel that Colt’s manufactures for all the M4A1 rifles used by our Special Operation soldiers. These carbines were manufactured exclusively for Specialized Armament Warehouse (SAW). As of this writing, this model had a one time run of 300 special order carbines manufactured by Colt for SAW. This is not to say at some point in the future Colt or SAW may offer it again as a special run or as a new product. The LE6920 began as a special run item and then turned into a regular product.


The LE6920 was test fired with Black Hills MK262 MOD 1 ammunition, which is the Special Operations Command (SOCOM) issue combat ammunition utilizing a Sierra 77-grain open-tip match bullet. Black Hills does offer a civilian equivalent cartridge as well. The reliability was flawless. Off a bench, accuracy remained less than 2 inches at 100 yards. All the controls are within hand’s reach and can be manipulated without the shooters hand ever leaving the pistol grip. Magazine changes and reloading can be accomplished in seconds due to the straight in placement of the magazine and the location of the bolt release.

With the addition of a reflex sight this carbine is ideal for any type of police/security work that may be required of it. With the availability of frangible ammunition (International Cartridge Company, Winchester Ranger and Federal Ballisticlean/AA40), the carbine is ideal for use in urban environments. The liability of over-penetration is massively decreased. This is the trend throughout the country, replacing the 9mm sub-guns with 5.56mm carbines. With a quick change of a magazine, the officer can have the penetration of a duty cartridge such as Hornady TAP, Federal TRU (Tactical Rifle Urban), Tactical Bonded (XM223T1, XM223T3) as well as the Winchester Ranger line of law enforcement ammunition that will pierce body armor and go through barriers. This versatility of the LE6920 is a major advantage to law enforcement.

Specifications: Colt LE6920 Carbine

Caliber: 5.56mm (.223 Rem)
Method of operation: Gas; direct system; locking bolt
Magazine capacity: 20 and 30-round box magazine
Fire control selection: Safe and semiautomatic
Effective range: 600 meters
Front sight: Adjustable
Rear sight: Target sight adjustable for windage and elevation
Flash hider: A2-style compensator
Upper receiver: Flat top receiver with Mill-Std 1913 rail and detachable carrying handle
Handguards: Oversized double heat shield

Contact List

Aimpoint, Inc.
3989 Highway 62 West, Suite 1
Bernville, AR 72616
(877) 246-7646

A.R.M.S., Inc.
Atlantic Research and Marketing Systems, Inc.
230 West Center Street
West Bridgewater, MA 02379
(508) 584-7816

Black Hills Ammunition
3050 Eglin Street
Rapid City, SD 57709
(605) 348-5150

Colt Defence, LLC.
P.O. Box 1868
Hartford, CT 06144
(800) 962-COLT

EOTech, Inc.
Electro-Optics Technologies
3600 Green Court, Suite 400
Ann Arbor, MI 48105-1570
(734) 741-8868

Federal Cartridge Company
900 Ehlen Drive
Anoka, MN 55303-7503
(800) 322-2342

International Cartridge Corporation
2273 Route 310
Reynoldsville, PA 15851
(877) 422-5332

Specialized Armament Warehouse (S.A.W.)
P.O. Box 6310
Chandler, AZ 85246-6310
(480) 940-7397

Trijicon, Inc.
49385 Shafer Avenue
P.O. Box 930059
Wixom, MI 48393
(800) 338-0563

This article first appeared in Small Arms Review V10N6 (March 2007)
and was posted online on February 7, 2014


Comments have not been generated for this article.