The Mk 18 is a short-barreled variant of the M4 carbine. Chambered in 5.56x45mm NATO and incorporates a 262mm (10.3in) barrel in comparison with the M4’s (14.5in) barrel. It’s the weapon of selection for CQB and when the utmost engagement distance is predicted to be lower than 300m.
On this information, you’ll study:
- The historical past of the Mk 18
- Why is the Mk 18 utilized by particular operations forces (SOF)
- Which SOF models use the Mk18
1. The Historical past of the Mk 18
The Mk 18 was initially referred to as the Shut Quarters Battle Receiver (CQBR). It was developed by the US Naval Floor Warfare Middle, Crane Division as a substitute higher receiver for M4 carbines issued to Navy SEALs. The M4 primarily splits in half into two receivers, the higher and the decrease. The higher incorporates the barrel and bolt service group, whereas the decrease incorporates the inventory and fireplace management group. The concept behind the CQBR program was to permit the person to shortly swap higher receivers based mostly on mission parameters. Nonetheless, the CQBR program developed from a easy higher receiver substitute into an entire firearm bundle: the Mark 18.
1.1. Mod 0
The unique Mk 18 mod 0/CQBR was primarily a cut-down M4. They each primarily make the most of the Knight’s Armament Firm-produced rail attachment system (RAS). The RAS has an inner clamping mechanism which permits any laser purpose module connected to it to retain zero. The handguard is light-weight and comparatively brief, filling the hole between the top of the receiver and the entrance sight block. Nonetheless, as a result of it attaches to the entrance sight block, any stress utilized to the handguard could cause a shift in accuracy. The mod 1 would remedy this situation.
1.2. Mod 1
The mod 1 makes use of the rail interface system II (RIS II), a free-floating railed handguard designed by Daniel Protection for the Mk 18 and M4. The RIS II utterly covers the barrel and solely contacts the barrel the place they meet on the receiver. This does two issues:
- The prolonged size permits the person to know additional out on the carbine, offering larger management whereas firing.
- The shortage of contact factors with the barrel offers larger accuracy and fewer point-of-aim/point-of-impact shift.
The RIS 2 additionally allowed the person to mount an M203 grenade launcher to their mod 1. The RIS II considerably improved the capabilities of the carbine. There’s a new variant of the carbine that has been seen within the wild, primarily utilized by Air Power SOF however has not obtained an official designation. It makes use of a shortened model of the M4 Higher Receiver Group – Improved’s (URGI) Mlok rail. That is considerably lighter than the RIS II rail whereas sustaining the advantages of size and free float. Nonetheless, it’s extra fragile and can’t mount an M203.
2. Why the Mk 18 is utilized by particular operations forces (SOF)
The Mk 18 is used and liked by SOF for a wide range of causes, most of which may be understood as quickly as you decide one up. The carbine’s small dimension makes it good for combating indoors or for carrying in autos. Though it sacrifices lethality on the vary when in comparison with the M4, the Mk 18’s most efficient vary is about 300m. Nonetheless when combating inside an city setting, sightlines may be fairly brief, typically lower than 100m. For SOF components conducting city raids in locations like Iraq and Afghanistan, the Mk 18 turned the right instrument for the job. The M4’s barrel size could make room clearing troublesome and the added lethality at vary typically goes unused throughout SOF raids. Because of this, the Mk 18 has change into the go-to weapon for particular operators combating in shut quarters.
3. Which SOF models presently use/have used the Mk18
The Mk 18 has seen use by mainly each unit in SOCOM and a few exterior of it. The Navy issued the Mk 18 to a few of its felony investigators that had been ahead deployed and the Coast Guard issued it out to a few of its boat crews. Nonetheless, particular operations forces have all the time been the first customers of the Mk 18.
