The G3 has a different system of operation, using rollers to delay the recoil until chamber pressure has diminished to a safe level before unlocking the breech and moving to the ejection and reloading portion of the cycle. This system is reliable and accurate, but very difficult, time consuming, and expensive to produce. Regardless of these difficulties, it was a design feature of many of HK's weapons.
The Rare FBI MP5 10mm with 2 round burst
By far the most famous of all HK's, the MP5 first became widely known when it was used by the SAS in the Iranian Embassy Rescue in London, 1980. It has been used widely by Special Forces, Law Enforcement and others ever since. Unlike many other submachine guns, the MP5 fires from the closed-bolt position, its ergonomics, accuracy, and reliability were far ahead of most if its rivals. It remains, 30 years or more after its design, one of the best weapons of its type.
The MP5 and its variants have been somewhat superseeded by the easier and cheaper to manufacture UMP series, available in 9mm, .40, and .45ACP, with a range of accessories, variants and even colors, the UMP is one of the most popular SMGs in the world today. Most UMPs have a folding stock, rails for the attachment of sights and forward grips, and a threaded barrel for suppressors, making the weapon very modular and adaptable to many needs.
HK has always been an innovator in the field of small arms, being the first to use polygonal rifling, which increases accuracy while protecting the barrel and giving it a longer useful life of many thousands of rounds.
Also, contrary to popular belief, they were the first to mass market a polymer-framed pistol. The VP-70 burst pistol, released in 1970 while it failed to become widely used (probably ' cause its ugly) it showcases the forward thinking of HK's engineers.
PSG-1 Marksman's Rifle with Nightvision Scope Attached
One of the latest developments from HK in the wake of the XM8 cancellation was the 416 and 417 rifles. Discarding the direct gas impingement system of Eugene Stoner's AR-15/ M16 series, they replaced it with a gas piston, greatly increasing reliability and parts life while decreasing the large amount of cleaning needed for the M16 series.
The HK 416, chambered in 5.56 NATO and the 7.62 NATO HK 417 have seen service with the Special Operations Forces in Iraq and Afghanistan and have all but replaced the M4 with US SOCOM. Perhaps soon the Pentagon will realize the many insurmountable failings of the M16 series and get a quality weapon into the hands of our troops. You know, or not.
This is one of HK's latest guns, the MP7A1, it is chambered in HK's own 4.6x30mm cartridge and the weapon was designed to better arm support troops than with a 9mm pistol that is difficult to shoot well, and easily defeated by soft body armor. The 4.6mm will pierce most vests that are Level IIIA or lighter and the weapon is designed to be worn in a holster like a pistol, but it can be steadied by extending the stock and folding down the fore grip. Seen here with a suppressor and Elcan red-dot sight, the MP7A1 would be in a good configuration for Special Forces in Urban areas, etc. The true effectiveness of the super small cartridges like the 4.6mm and the 5.7 are still up in the air, however.