Mk-18 Mod 0 Mjolnir Ar 338 Lapua Semi Autoreal Review
| Close Quarter Boxing Receiver[ane] | |
|---|---|
 Top: An M4A1 with SOPMOD package, including Rail Interface Arrangement and Trijicon 4× ACOG. The barrel length is 14.5 inches (368 mm). | |
| Type | Assault Burglarize Carbine |
| Place of origin | United States |
| Service history | |
| In service | 2000–nowadays[ citation needed ] |
| Used by | See M4 Carbine users |
| Wars | War in Transitional islamic state of afghanistan Iraq War |
| Production history | |
| Designer | Filly Defense,Daniel Defense force.[two] |
| Designed | 1999[ citation needed ] |
| Produced | 2000–present[ citation needed ] |
| No. built | Approx. >10,000 |
| Specifications (CQBR) | |
| Mass | ii.72 kg (6.00 lb) |
| Length | 762 mm (30.0 in) stock extended 679.4 mm (26.75 in) stock retracted |
| Butt length | 262 mm (x.iii in) |
| | |
| Cartridge | 5.56×45mm NATO |
| Action | Gas-operated, rotating bolt |
| Charge per unit of fire | 700–950 round/min cyclic |
| Muzzle velocity | 2,585 ft/s (788 m/south)[3] |
| Constructive firing range | 300 m (328 yd) |
| Feed system | twenty- or thirty-circular detachable STANAG mag |
| Sights | Iron sights and various SOPMOD sights |
The Close Quarter Battle Receiver (CQBR) is a replacement upper receiver for the M4A1 Carbine, developed by the US Navy.
The CQBR features a 10.3 in (262 mm) length barrel (similar to the Colt Commando short-barreled M16 variants of the past) which makes the weapon significantly more compact, thus making it easier to use in, and around, vehicles and in tight, confined spaces. The overall length of the upper receiver is 19.25 inches (489 mm). With the stock retracted, the overall length of the weapon is 26.75 inches (679.iv mm).
Special forces units utilize the CQBR for scenarios such as VIP protection, urban warfare, and other close quarters boxing (CQB) situations.
Its former preliminary National Stock Number (NSN) had been 1005-LL-L99-5996. A complete CQBR-equipped carbine now has the NSN 1005-01-527-2288.
Groundwork [edit]
The M4 carbine and M16 are not ideally suited for all missions due to their relatively long barrels, merely the modularity of AR pattern rifles allows the operator to hands supercede the upper receiver. 1 of two proposed special mission receivers that were planned for inclusion into the SOPMOD Block 2 kit, the CQBR has taken off on its own. Similar the proposed Special Purpose Receiver, the Shut Quarters Boxing Receiver has been more or less taken on by the Naval Surface Warfare Heart, Crane Partitioning (often referred to as NSWC-Crane or just "Crane") as its own project following the CQBR'due south removal from the SOPMOD program. Just every bit the Special Purpose Receiver morphed into the Special Purpose Rifle, and was type-classified equally Mk 12 Modern 0/one, the complete CQBR-equipped carbine has been type-classified equally the Mk 18 Mod 0, or the Mk 18 Mod 1 with a sightless gas cake and full-length accessory track kit.
The purpose of the CQBR remains to provide operators with a weapon of submachine gun size, but firing an intermediate 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 commonly issued as a complete weapon arrangement, and not only an upper receiver. The CQBR was once only bachelor to Naval Special Warfare units (and by extension, other United states Special Operations Forces units), but the Mk eighteen Mod 0 has get general consequence for Visit, Board, Search, and Seizure (VBSS) missions and, as of 2006, for NCIS agents deploying to active combat zones.[ citation needed ] The Mk eighteen is also used by the Coast Guard's Tactical Police force Enforcement Teams and Maritime Security Response Teams and the U.s. Navy's Explosive Ordnance Disposal (EOD) Operators. Information technology is also used by both Marine Force Recon'south CQB operators and Critical Skills operators from MARSOC, and is in most cases the standard weapons of choice for said operators where the range and accuracy of an M4 is not necessary.
The short 10.3 in (262mm) barrel length requires special modifications to reliably function. The gas port is opened from 0.062 to 0.070 in (1.6 to 1.8mm). A jumpsuit McFarland gas ring replaces the three-piece gas ring set. The standard four-whorl extractor spring is replaced with a commercial off-the-shelf (COTS) five-coil spring. An O-band surrounds the extractor spring. The standard M4 wink hider has been replaced with the M4QD wink hider for suppressor compatibility.
Ballistic performance [edit]
Shortening the barrel past fifty% from the original 20 inches (508 mm) pattern has a dramatic consequence on the velocity of v.56x45mm NATO ammunition. With a 20" barrel, the bullet is moving at three,071 ft/due south (936 m/s), but this drops to 2,489 ft/s (759 m/south) at x".[4] This has pb some to question the effectiveness[v] of the Mk xviii compared to other cartridges like 7.62×39mm or .300 AAC Blackout which are not every bit affected by barrel length reduction.
| Model | Barrel length in inches | Cage velocity (feet per 2d) | Change in velocity from 26" (feet per second) |
|---|---|---|---|
| 26 | 3182 | ||
| M16 | 20 | 3071 | -111 |
| xvi.5 | 2968 | -214 | |
| Mk 18 | ten | 2489 | -693 |
Evolution [edit]
- 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 fourth dimension of build, will work with H, H2 or H3 balanced to ammo requirements:
- H okay with M193/M855.
- H2 needed for MK 262/R2LP and will feed and fire M193/M855.
- H3 may be needed for an extreme case, or when the gas port is eroded but the butt still groups.
- CQBR type 2A: NSWC assembled with contracted and /or overhauled parts, naked without whatsoever accessories or buffer. The buffer in the host carbine would be used or upgraded equally necessary via the supply system same every bit 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 equally necessary via the supply system aforementioned 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 every bit necessary via the supply system same equally blazon two.
- MK18 type 1: NSWC assembled carbine with contracted and/or overhauled parts complete with all accessories to electric current standards at time of build; volition piece of work with H or H2 and could have shipped with either. Units volition residual buffer to ammo requirements:
- H okay with M193/M855. (All shipboard MK 18s should have H buffers every bit this was the standard at the time of associates.)
- H2 needed for MK 262/R2LP and volition run M193/M855.
- H3 may exist 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 residual buffer to ammo requirements same as Mk 18 type one.
- MK18 Mod i: Similar to the changes found in the SOPMOD Block II kit, the Mod one features a gas block finish without a front sight and a railed handguard, past Daniel Defense, that extends all the way to the base of the wink hider to provide more accessory track space for the user.
- MK18 Mod ii: Simultaneously with USASOC's adoption of the Upper Receiver Group, Improved (URG-I), which featured the Geissele Automatic's MK16 rails with M-LOK interface, Special Operations community had requested Geissele to develop a nine.3-inch rail for their MK18 Modernistic 2'due south. In 2019, in that location were requirements for a x.5-inch rail instead, because reevaluation plant xi.five-inch barrels to work better than 10.3-inch serial, and thus a longer rail is needed. Together with the regular fourteen.5-inch uppers, these are frequently unofficially dubbed "SOPMOD Block three" past operators.
Specifications [edit]
Navy SEALs bear Shoot Firm Grooming at Little Creek, Virginia in mid 2007. Each Mk18 Modernistic 0 CQBR carbines has the M68 Aimpoint optic, Knight'due south Armament QD suppressor and AN/PEQ-2.
- Upper and lower receivers: The lower receiver is a standard M4A1 lower receiver sometimes modified with the improver of a CQD RSM sling adapter plate. However, many CQBR rifles also utilise surplus M16A1 lower receivers. Internally, the CQBR also takes advantage of a larger gas port and modified bolt carrier and buffer associates. The gas port has been opened to 0.070 in (i.8 mm). A number of Lewis Machine & Tool 10.5" (266.seven mm) upper receivers take as well been reported to accept been purchased for the CQBR program. These upper receivers characteristic a gas system optimized for short butt apply. The Modern 1 makes use of a forward sight delete and full-length handguard to provide more runway space for the user.
- Sights: Initially, detachable carrying handles cutting down and then that simply the rear sight assembly was used. All the same, nearly of these have been replaced with the like, commercially-made Lewis Machine & Tool adjustable rear sight. Too used are several types of reflex and magnified eyes, nearly normally seen is the Aimpoint CompM2 in a Wilcox Industries Corp. Picatinny (MIL-STD-1913) mount. On the Mod 1, the front sight is deleted and a total-length accompaniment rail is used; flip upwards iron sights may be mounted per user preferences
- Stock: A multifariousness of M4 retractable buttstocks are used on a standard four-position receiver extension, including the standard "Auto" stock. About often seen is the SOPMOD stock, often referred to every bit the "Crane stock", created by Dave Armstrong of NSWC-Crane. The angled stock offers better cheekweld likewise every bit 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 drinking glass cobweb polymer. Considering of this, they were somewhat fragile and did not e'er properly lock into the receiver extension. A safe band was used to secure the latch so it would not slide out of the desired position. The electric current L7LA2B SOPMOD stocks are made past Lewis Motorcar & Tools and accept none of these problems.
- Barrel: The CQBR uses a i:seven in (178 mm) twist M4 barrel that has been modified in length to 10.3 in (262 mm). The diameter of the butt under the handguards is one.17 in (29.7 mm). The KAC M4-QD wink suppressor is fitted, allowing employ 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 a bayonet.
- 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 diverseness of butt profiles and allows for the use of whatever MIL-STD-1913 tactical accessories such as the AN/PEQ-ii infrared pointer, SureFire flashlights, or a vertical forward grip.
The handguard manufacturer has since changed from KAC to Daniel Defense every bit the master contractor for the MK18 RIS, NSN # 1005-01-548-1385.
- Ammunition: The CQBR is designed to use standard five.56×45mm NATO 62-grain SS109/M855 FMJ and M856 Tracer armament. However, due to the brusque barrel, the heavier 77-grain Mk 262 cartridge is preferred. At that place are no plans to rechamber the weapon in any boosted calibers.
See also [edit]
- AR-15
- Listing of private weapons of the U.Due south. Armed Forces
- Listing of attack rifles
- Usa Army Special Forces
References [edit]
- ^ a "NSWC Crane Saves $970K for NAVSEA Minor Arms Office"
- ^ [1],
- ^ NAVSEA CQBR PowerPoint presentation
- ^ Marr, Bill (7 December 2015). "223 Remington/ 5.56mm NATO barrel length and velocity: 26 inches to half-dozen inches". rifleshooter.com . Retrieved 29 June 2021.
- ^ Is the MK18 obsolete?, archived from the original on 12 December 2021, retrieved 29 June 2021
External links [edit]
-
Media related to Close Quarters Battle Receiver at Wikimedia Eatables - NAVSEA CQBR PowerPoint presentation
- Wilcox Industries Corp.
- Minor Arms Review
Source: https://en.wikipedia.org/wiki/Close_Quarters_Battle_Receiver
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