HK 416

[kaur3]

How to soldier: Heckler & Koch’s HK416 upgrade tackles the M4 and M16.
Form Jane’s International Defence Review, Oct. 2005.

By Charles Q Cutshaw

It is fairly common knowledge that the special operations community has long had reservations about the M4A1 Carbine. Lethality problems first surfaced in 1993, when Somali gunmen who had been repeatedly shot by Delta Force soldiers were able to continue fighting.
But lower than expected lethality is not the only issue with the M4A1. According to a 2001 Special Operations Command study, changing the M16 to a short-barrelled car- bine configuration creates a mechanism that approaches or exceeds the weapon's limits. The study states that all M 16-derived car- bines are "fundamentally flawed" for a variety of reasons. Shortening the gas tube gives rise to several undesirable side-effects, including early timing, in which the bolt is unlocked and moving to the rear while the cartridge case is still adhering to the chamber wall under residual pressure from the fired round. This causes failures to eject, separated case heads and other malfunctions.
The M4A1 has generally required intensive maintenance by its Special Forces users to keep it operational. Such problems have not arisen in the more common M16 series rifles because the latest M16A2 versions fire three-round bursts, which limits stress on the rifle, and because problems that are inherent in the carbine do not exist in full-length rifles.
Quality control
The main users of carbines are special operations units; and the nature of the missions these elite units undertake often leads to their M4A1 carbines being used in ways that were not envisaged when they were designed. Special operations users frequently have to lay down heavy volumes of fire to break contact with larger enemy forces. They also often add relatively heavy accessories to their carbines under the Special Operations Peculiar Modification (SOPMOD)XModular Weapon System (MWS) Programmes. The addition of such accessories not only adds weight to the weapon, but can also reduce its reliability. According to the study, the M4Al's reliability has been further compromised by a decline in quality control.

Specific M4A1 deficiencies include problems with reliability, safety, accuracy and ergonomics. Reliability problems have included failure to extract, failure to eject, broken bolts, failure to function in extreme cold and severe malfunctions in over-the-beach operations. Safety-related issues have included frequent cookoffs, burst barrels and burst receivers when the M4A1 has been used in over-the-beach or riverine operations and the barrel has filled with water.
Accuracy problems have included barrels becoming loose or shot out after firing a relatively low number of rounds, rail systems not retaining zero and general difficulties controlling the M4A1 in full automatic.

From an ergonomic standpoint, problems have been identified with a poor cheek-weld area on the butt-stock, , lack of ambidextrous controls, poor pistol grip and vertical foregrip geometry, and "multiple ergonomic deficiencies in the SOPMOD/ MWS systems". The most serious problems have involved jamming and overheating. Ultimately, it was concluded that a complete redesign of the M4A1 would be necessary to resolve the inherent issues - a programme with an estimated cost of up to USD2 million. Although a carbine reliability parts set was developed to address the issues identified, it was no more than a 'band aid' on a system that SOCOM considered to be flawed.

Another fundamental problem with the basic AR (Armalite Rifle) design arises from Stoner's use of a gas system similar to that of the Swedish Ljungman. This blows fouling and gases back into the rifle's receiver: a major flaw that makes the rifle sensitive to ammunition certain types of ammunition, which can generate quantities of carbon fouling, causing serious problems.
The US Army learned this lesson early as it specified ball powder for 5.56x45mm military ammunition. This powder quickly fouled the receiver and, in combination with some other misunderstandings regarding the M16A1, resulted in the deaths in combat of soldiers and Marines whose rifles ceased to function due to fouling, earning the rifle a reputation for poor reliability.
The fouling problem was quickly rectified by switching powders, but the basic AR remains a 'dirty' gun that requires intensive cleaning and maintenance. An entire generation of US service personnel has grown accustomed to this as the norm, although older military hands recall the American Ml and M14, FAL/L1A1 and Heckler & Koch (H&K) G3, which did not need the the high level of maintenance required by theM16.
Over the years there have been many attempts to rectify this inherent M16 operating system design deficiency by substituting gas piston and operating rod systems, with mixed success. But when Army Special Operations began looking for a product improvement for the M4, H&K offered to undertake the programme at no cost to the government, other than the loan of 10 carbines as Government Furnished Equipment through a contract with USSO-COM, for assessment.
After a detailed assessment of the carbine's general design and the issues already identified by the military, H&K proposed numerous modifications to improve the weapon's accuracy, safety, ease of maintenance, ergonomics, modularity and commonality of parts, using the performance of

the H&K G36 as a benchmark. H&K aimed to increase the reliability and component service life of the basic weapon by a factor of two to three times.
The HK416 began operational use in combat in 2005 with several special operations units and has successfully met all requirements. In a recent military acceptance test, a 254 mm barrelled HK416 fired more than 15,000 rounds without suffering a stoppage or parts failure. After 12,000 rounds, the carbine was capable of firing one inch, five-round groups at 100 m from a rest, using match grade ammunition. The test sample carbine had fired over 20,000 rounds as of June 2005 without suffering a failure, or a degradation in velocity or accuracy of more than five per cent.
So what has H&K done to make such a dramatic upgrade to the M4's reliability? Apart from the addition of a new buffer and drive spring, the modifications have all been made to the upper receiver. The Ljungman direct impingement gas system has been replaced by a piston and operating rod taken from the G36, which is itself an improved version of the proven AR-18 piston and operating rod system. This new operating rod system is the most significant single improvement in the weapon and is responsible for much of its increased reliability.
Overheating has also been dramatically reduced. When the M4A1 carbine is fired extensively in full automatic, hot gases that are blown back into the receiver can cause overheating, which in extreme cases may cause the barrel to loosen or stretch. When the latter occurs, the barrel can become bent, which can cause bullets to shoot out the side of the barrel. Overheating can also cause failures to extract and other problems. The operating rod system eliminates many of these problems along with the carbon fouling. The H&K system also eliminates the gas rings that surround the bolt, which are themselves problematic when they wear or get out of alignment.
Smooth carbine operation H&K has also developed an improved buffer and drive spring that smoothes the carbine's operation and reduces the cyclic rate to approximately 650 rounds per minute. The MIL-STD-1913 rail hand-guard is fully free-floated and retains bore sight when removed and replaced. The improved H&K handguard can be removed and replaced in less than a minute, without the use of special tools. HK416 barrels are cold-hammer forged and chrome lined.
The guns that have both upper and lower receivers manufactured by H&K also have some extra improvements: the buffer retention in the lower receiver has been modified and improved; and the magazine well has been flared to facilitate inserting magazines during quick changes.
H&K diopter-type sights have also been added, with a folding front sight and a removable rear sight that is fully adjustable for windage and elevation via the traditional H&K rotating drum system.
H&K-developed magazines that can be used with any AR-type rifle or carbine afford another significant improvement. The original aluminium AR magazines were designed to be disposable, but in reality they have often been used repeatedly. This presents two problems: they wear out relatively quickly as a result of their thin aluminium construction; and their openings allow access to dust and debris.
Although some modifications have been made to the original magazine design over the years, there had been no fundamental changes until H&K undertook a redesign. H&K magazines are all steel, with a completely new follower that will not 'nosedive', even when pushed as far to the front as possible. The feed lips have been modified to provide improved feed, as have the guide ribs, and there are no external openings in the magazines, except for a small opening at the top where the follower moves up and down.
This lack of openings means that when the H&K magazine is attached to the rifle there is no place for dust to enter. The magazine spring has also been redesigned and the magazine reconfigured somewhat. This is readily noticed when standard magazines and H&K magazines are placed side-by-side. Both 20 and 30 round versions of the magazine are available.

Room for improvement

Shooting the HK416 reveals just how much room for improvement there was with the
basic M4 design. Accuracy is excellent in both full and semi-automatic and the smooth operation of the HK416 in full automatic is remarkable. Muzzle rise is virtually nonexistent and the reduced cyclic rate makes it easy to squeeze controlled bursts.

Anyone familiar with the M16 or M4 has nothing new to learn when presented with an HK416. The manual of arms is the same, so there is virtually no learning curve. What is different, however, is how the HK416 transforms the M4 platform - it is essentially a new weapon that completely outperforms the current M4.
The HK416 can be purchased as a simple upper receiver replacement upgrade with an H&K buffer and drive spring that brings existing Ml6s or M4s up to HK416 standard, enabling organisations that already have Ml6s or M4s to obtain what is essentially a new and dramatically improved weapon for the cost of these components. The upgrade can be accomplished in seconds and there are no training issues. For those who want a completely new weapon, the HK416 is also available in that configuration.

Another new addition is H&K's enhanced grenade launcher module (EGLM) that mounts on the HK416's bottom MIL-STD-1913 rail in a matter of seconds, without the need for any tools, This 40x46 mm launcher opens to the side so that it is not restricted to short 40 mm rounds, as is the case with the M203. The EGLM, like the HK416, is fully ambidextrous and can be fired either on the carbine or as a stand-alone grenade launcher. When the EGLM is removed from the carbine and replaced, it retains zero. The EGLM is compatible with any weapon with a MIL-STD-1913 bottom rail. A shorter version of the EGLM has recently been adopted by the US Army, with the designation XM320. The author found the EGLM straightforward to use with minimal instruction on the weapon and its sighting system.
H&K has transformed the M4A1 carbine into a completely new weapon, which resembles the M4 externally but has internal modifications that make it far superior to the current M4A1. The HK416 is more reliable, more accurate, easier to maintain and has a service life of two to three times mat of the M4. It is adaptable to either M4 carbines or M16 rifles and is available in barrel lengths of 254,368,419 and 508 mm.
All HK416 barrels have a twist rate of one turn in 178 mm. The simplicity and economy of converting existing weapons by changing upper receivers cannot be emphasised enough. In the final analysis, we can only wonder why something like the HK416 had not been undertaken before, since the problems associated with the M4 carbine have been known for years. With the HK416 modification, the M4 and M16 should be capable of soldiering on foranother 50 years.

[kaur3]

Siin on artikkel acrobat readeriga
http://www.hkdefense.us/corporate/media ... _Oct05.pdf

[kaur3]

"Better than M4, but you can’t have one"

http://www.armytimes.com/news/2007/02/atCarbine070219/

Video.

http://www.armytimes.com/projects/video ... 19carbine/

[Medusa]

Paistab kobe asi olevat, kahju vaid et eestisse nii lihtsalt osta ei saa, ühe 7.62x51 täpsusversiooni vastu poleks midagi

[kaur3]

4.13.2007: The Norwegian Army adopts HK416 and places order for 8,200 units. After 11 years, the search for a rifle to replace the AG-3 is over. First units expected to be delivered in November. Order is worth $16.7 million. New rifles to be fitted with Aimpoints in an order worth $8.3 million.

http://www.hkpro.com/