Weapon Name- Mk. M4 Mod 5 (KH416)
Round Type- 6.8mm Remington
Over-all length- 36.9 inches, 33 stock inches retracted
Barrel length- 16 inches
Weight- 7.9 lb (3.6 kg) empty
Rate of Fire- 560 to 640 rpm
Feed Mechanism- Detachable Box Magazine
Round Capacity- 28, 30, or 56 round surefire magazine or 100 round drum magazine
Effective Range- 500 meters
Range- 800 meters
Accuracy- 1-2 MOA
Accessories- Picanty Rail
Quick switch firing mechanism- N/A
Scope/Sights- Picanty Rail
Muzzle Velocity- 785 m/s (7.45 grams)
Miscellaneous/electronic information- The weapon is essentially the HK416, based off of the M27 IAR, and designed to use 6.8mm Remington rounds
Basic Information
The weapon is essentially the M27 IAR model HK416, which is considered to be a modified M4 carbine.
The weapon sports a heavy, 16.5 inch 6.8mm Remington hammer forged barrel. The weapon also uses and improved, extremely reliable gas operated short stroke piston operation. The weapon sports an additional feature, similar to the HK53 and Ares shrike rifles, which is a belt fed adapter, allowing the weapon to use basic M27 links (and ones modified for 6.8mm Remington rounds) if necessary.
The HK416 uses a proprietary gas system derived from the HK G36, replacing the direct impingement gas system used by the standard M16/M4. The HK system uses a short-stroke piston driving an operating rod to force the bolt carrier to the rear. This design prevents combustion gases from entering the weapon’s interior, a shortcoming with direct impingement systems. The reduction in heat and fouling of the bolt carrier group increases the reliability of the weapon and extends the interval between stoppages. It also reduces operator cleaning time and stress on critical components. The SA80 bull-pup assault rifle used this system long before the HK G36 was developed. According to H&K "experience that Heckler & Koch gained during its highly successful 'midlife improvement programme' for the British Army SA80 assault rifle, have now borne fruit in the HK416.".
The HK416 is equipped with a proprietary accessory rail forearm with MIL-STD-1913 rails on all four sides. This allows most current accessories, used on M4/M16-type weapons, to be fitted to the HK416. The HK416 rail forearm can be installed and removed without tools by using the bolt locking lug as the screwdriver. The rail forearm is 'free-floating' and does not contact the barrel, improving accuracy.
The HK416 has an adjustable multi position telescopic butt stock, offering 6 different lengths of pull. The shoulder pad can be either convex or concave and the stock features a storage space for maintenance accessories, spare electrical batteries or other small kit items.
The trigger pull is 34 N (7.6 lbf). The empty weight of a HK416 box magazine is 250 g (8.82 oz).
The HK416's barrel is cold hammer-forged with a 20,000 round service life and features a 6 grooves 178 mm (7 in) right hand twist. The cold hammer-forging process provides a stronger barrel for greater safety in case of an obstructed bore or for extended firing sessions. This includes "OTB" (Over-the-beach) capability; the HK416 can be safely fired after being submerged in water and not completely drained.
In July 2007, the US Army announced a limited competition between the M4 carbine, FN SCAR, HK416, XCR, and the previously-shelved HK XM8. Ten examples of each of the four competitors were involved. Each weapon fired 60,000 rounds in an "extreme dust environment." The purpose of the shoot-off was for assessing future needs, not to select a replacement for the M4. The XM8 scored the best, with only 127 stoppages in 60,000 total rounds, the FN SCAR Light had 226 stoppages, while the HK416 had 233 stoppages. The M4 carbine scored "significantly worse" than the rest of the field with 882 stoppages. A member of the AWG armed with a Heckler & Koch HK416 in Iraq (bottom right).
The HK416 was one of the weapons displayed to U.S. Army officials during an invitation-only Industry Day on November 13, 2008. The goal of the Industry Day was to review current carbine technology prior to writing formal requirements for a future replacement for the M4 carbine.
In December 2009, a modified version of the HK416 was selected for the final testing in the Infantry Automatic Rifle program, designed to partially replace the M249 light machine gun at the squad level for the United States Marine Corps. It beat the three other finalists by FN Herstal and Colt Defense. In July 2010, the HK416IAR was designated as the M27, and 450 were procured for additional testing.
The Norwegian Army made an extensive evaluation before selecting the HK416 as its new primary firearm.
