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Encyclopedia > CQBR
A CQBR in comparison to a standard M4A1, showing how the reduced barrel length creates a more compact rifle.
A CQBR in comparison to a standard M4A1, showing how the reduced barrel length creates a more compact rifle.

The Close Quarters Battle Receiver (CQBR) is a replacement upper receiver for the M4A1 Carbine. The CQBR upgrades the M4 with a barrel 10.3 in (260 mm) long, the modern equivalent of the Colt Commando short-barrel M16 variants of the past. Image File history File links Above: A M4A1 with SOPMOD package, including Rail Interface System and Trijicon 4x ACOG. The barrel length is 14. ... Image File history File links Above: A M4A1 with SOPMOD package, including Rail Interface System and Trijicon 4x ACOG. The barrel length is 14. ... This article does not cite its references or sources. ... M4A1 redirects here. ... Caliber: 5. ...


It's preliminary National Stock Number was 1005-LL-L99-5996; however, a complete CQBR-equipped carbine now has the NSN 1005-01-527-2288. The overall length of the upper receiver is 19.25 inches (489 mm). With the stock retracted, the overall length of the weapon is 26.25 inches (666 mm). The CQBR entered service in 2000. Folding stock of a SIG 550 rifle A stock or buttstock or shoulder stock is present in many firearms and some crossbows, and performs three functions - to facilitate easy and steady holding and aiming of the weapon prior to and during firing (which may be further assisted by a sling...

Contents

Background

The M4 and M16 are not ideally suited for all missions, so it was proposed that the modularity of the M16 series would allow a user to replace the upper receiver of an existing weapon with one more suitable to the task. One of two proposed special mission receivers that were planned for inclusion into the SOPMOD Block II kit, the CQBR has taken off on its own. Like the proposed Special Purpose Receiver, the Close Quarters Battle Receiver has been more or less taken on by the Naval Surface Warfare Center, Crane Division (often referred to as NSWC-Crane or just "Crane") as its own project following the CQBR's removal from the SOPMOD program. Just as the Special Purpose Receiver morphed into the Special Purpose Rifle, and was type-classified as Mk 12 Mod 0/1, the complete CQBR-equipped carbine has been type-classified as the Mk 18 Mod. 0. The Special Operations Particular Modification (SOPMOD) kit is an accessory system for the M4A1 Carbine used by USSOCOM. The kit allows the Special Forces operator to configure his weapon to individual preferences and mission requirements. ... Naval Surface Warfare Center Crane Division is a United States Navy installation located approximately 70 miles (113 km) southwest of Indianapolis, Indiana and predominantly located in Martin County. ... An Mk 12 Mod 0 SPR clone built by Mid-South Tactical Network (MSTN). ...


The purpose of the CQBR remains to provide operators with a weapon of submachine gun size, but firing a rifle cartridge, for scenarios such as VIP protection, urban warfare, and other close quarters battle (CQB) situations. The CQBR is designed to provide improvement over previous AR-15/M16-type weapons in this category. The CQBR is usually issued as a complete weapon system, and not just an upper receiver. The CQBR was once only available to Naval Special Warfare units, but the Mk 18 Mod 0 has become general issue for Visit, Board, Search, and Seizure (VBSS) missions. NCIS agents deploying to active combat zones are also issued the Mk 18 as of summer 2006. The MP5 is a third-generation submachine gun that is widely used by law enforcement tactical teams and military forces. ... For other uses, see Rifle (disambiguation). ... This article does not adequately cite its references or sources. ... It has been suggested that this article or section be merged with MOUT. (Discuss) CQB, sometimes CQC, is an acronym for Close Quarters Battle or Close Quarters Combat, and refers to fighting methods within buildings, streets, narrow alleys and other places where visibility and maneuverability are limited. ... The AR-15 is a lightweight, air-cooled, magazine fed, autoloading, centerfire rifle. ... M16 (more formally United States Rifle, Caliber 5. ... NAVSPECWARCOM logo. ...


The short 10.3 in (262 mm) barrel length requires special modifications to reliably function. The gas port is opened from 0.062 to 0.070 in (0.16 to 0.18 mm). A one-piece McFarland gas ring replaces the three-piece gas ring set. The standard 4-coil extractor spring is replaced with a commercial off-the-shelf (COTS) 5-coil spring. An O-ring surrounds the extractor spring.


Evolution

  • CQBR type 1 - Made from M4A1 uppers by shortening the barrels and opening gas ports, no longer produced , STD carbine buffer in use in host lowers at time of fielding.
  • CQBR type 2 - NSWC assembled with contracted and /or overhauled parts complete with all accessories to current standards at time of build, will work with H, H2 or H3 balanced to ammo requirements:
  • H ok with M193/M855.
  • H2 needed for MK 262/ R2LP & will run M193/M855.
  • H3 may be needed for an extreme case, or when the gas port is eroded but the barrel still groups.
  • CQBR type 2A - NSWC assembled with contracted and /or overhauled parts, naked without any accessories or buffer. The buffer in the host carbine would be used or upgraded as necessary via the supply system same as type 2.
  • CQBR type 3 - Colt contracted upper complete with all accessories. NO buffer supplied. The buffer in the host carbine would be used or upgraded as necessary via the supply system same as type 2.
  • CQBR type 3A - Colt contracted upper naked without any accessories or buffer supplied. The buffer in the host carbine would be used or upgraded as necessary via the supply system same as type 2.
  • MK18 type 1 - NSWC assembled carbine with contracted and /or overhauled parts complete with all accessories to current standards at time of build will work with H or H2 and could have shipped with either. Units will balance buffer to ammo requirements:
  • H ok with M193/M855. ( all ship board MK 18’s should have H buffers as this was the standard at the time of assembly).
  • H2 needed for MK 262/ R2LP & will run M193/M855
  • H3 may be needed for an extreme cases or when the gas port is eroded but the barrel still groups
  • MK18 type 2 - Colt contracted carbine complete with all accessories H buffer supplied .Units will balance buffer to ammo requirements same as MK18 type1.

Specifications

  • Upper and lower receivers: The lower receiver is a standard M4A1 lower receiver sometimes modified with the addition of a CQD RSM sling adapter plate. Internally, the CQBR also takes advantage of a larger gas port and modified bolt carrier and buffer assembly. The gas port has been opened to 0.070 in (0.18 mm). A number of Lewis Machine & Tool 10.5" (266.7 mm) upper receivers have also been reported to have been purchased for the CQBR program. These upper receivers feature a gas system optimized for short barrel use.
  • Sights: Initially, detachable carrying handles cut down so that only the rear sight assembly was used. However, most of these have been replaced with the similar, commercially-made Lewis Machine & Tool adjustable rear sight. Also used are several types of reflex and magnified optics, most commonly seen is the Aimpoint CompM2 in a Wilcox Industries Corp. Picatinny mount.
  • Stock: A variety of M4 retractable buttstocks are used on a standard 4-position receiver extension. Most often seen is the SOPMOD stock, often referred to as the "Crane stock", created by Dave Armstrong of NSWC-Crane. The angled stock offers better cheekweld as well as providing two storage compartments for spare batteries. The stock must be removed from the weapon to access the storage compartments. The initial run of stocks was made by NSWC-Crane from glass fiber polymer. Because of this, they were somewhat fragile and did not always properly lock into the receiver extension. A rubber band was used to secure the latch so it would not slide out of the desired position. The current SOPMOD stocks are made by Lewis Machine & Tools and have none of the problems.
  • Barrel: The CQBR uses a standard 1:7 in (178 mm) twist M4 barrel that has been reduced in length to 10.3 in (262 mm). The diameter of the barrel under the handguards is 1.17 in (29.7 mm). The KAC M4-QD flash suppressor is fitted, allowing use of the KAC QDSS-NT4 suppressor (National Stock Number 1005-01-437-0324). Although it has a bayonet lug, the CQBR is not meant to be fitted with any fighting blades.
  • Handguards: The standard handguard for the CQBR is the Knight's Armament Company Rail Interface System (M4 Carbine RIS; National Stock Number 1005-01-416-1089), which is designed for a variety of barrel profiles and allows for the use of any MIL-STD-1913 tactical accessories such as the AN/PEQ-2 infrared pointer, SureFire flashlights or a vertical forward grip.
  • Ammunition: The CQBR is designed to use standard 5.56x45mm NATO 62-grain M855 FMJ and M856 Tracer ammunition. However, due to the short barrel, the heavier 77-grain Mk 262 cartridge is preferred. There are no plans to rechamber the weapon in any additional calibers.

Looking down the iron sight of an M15A4 Carbine (a civilian copy of the M4 carbine) The term iron sights refers to the open, unmagnified aiming system used to assist the aiming of a variety of devices, usually those intended to launch projectiles, such as firearms, airguns, and crossbows; they... The CompM2 is a red dot gunsight manufactured by Aimpoint AB. Its US Army designation is M68 Aimpoint. ... M4A Modular Weapons System carbine with M1913 rails on receiver and foregrip Picatinny Rail Dimensions, Cross Section The Picatinny rail is a bracket used on some firearms in order to provide a standardized mounting platform for scopes and other accessories such as tactical lights and laser sighting modules. ... Close-up of the flash suppressor on a Sig 550. ... For other uses, see bayonet (disambiguation). ... Knights Armament Company (KAC, also Knights Manufacturing Company) is an American firearms and firearms parts manufacturer. ... M4A Modular Weapons System carbine with M1913 rails on receiver and foregrip Picatinny Rail Dimensions, Cross Section The Picatinny rail is a bracket used on some firearms in order to provide a standardized mounting platform for scopes and other accessories such as tactical lights and laser sighting modules. ... The AN/PEQ-2 is a laser aiming device for use on rifles fitted with a Picatinny rail. ... For other uses, see Infrared (disambiguation). ... Surefire U2 digital variable-output LED flashlight Surefire is a California-based company that produces precision tactical flashlights commonly used in the law enforcement and military fields. ... U.S. Military 5. ... Calibre redirects here. ...

Photos

See also

us army photo of M-16a2 rifle (not copyrightable) File links The following pages link to this file: M16 (rifle) User:Avriette/My Images Categories: U.S. military images ...

  Results from FactBites:
 
KWA M4 CQBr/ ECHO1 outer barrels? (454 words)
heres and ECHO1 CQBr length outer, with an extender to make it M4 length, that $50 from ASGI, where i will be orderign my gun from, and then there a KA reinforced one but it doesnt have the extender for $53 shipped.
I beleive i saw it in the low 330 on on another forum They did that for the whole reason as in the cqb in its name.
And it wouldnt be a cqbr if you just put a ris on the front.
Spartanburg SC | GoUpstate.com | Spartanburg Herald-Journal (910 words)
The CQBR upgrades the M4 with a barrel 10.3 in (260 mm) long, the modern equivalent of the Colt Commando short-barrel M16 variants of the past.
The purpose of the CQBR remains to provide operators with a weapon of submachine gun size, but firing a rifle cartridge, for scenarios such as VIP protection, urban warfare, and other close quarters battle (CQB) situations.
Although it has a bayonet lug, the CQBR is not meant to be fitted with one.
  More results at FactBites »


 
 

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