The HK 417 began as a privately-funded company venture intended to supply US special forces with a modular battlefield weapons system. The HK 417 model shares a visual and functional similarity to the previous Heckler & Koch offering, the HK 416, which itself was developed to compete with the M4 carbine and M16 assault rifles of the regular army. While the HK 416 is chambered for the widely-accepted 5.56mm cartridge, the HK 417 makes use of the traditional rifle-caliber 7.62x51mm NATO standard cartridge. Despite the HK 417 still being in its final development phase officially, it has already been fielded in an operational role with US special forces in the Iraq and Afghanistan theaters.
The HK 417 retains much of the form and function of the preceding HK 416 series and, as such, showcases several of the same integral components and functionality. Like the HK 416 before it - and the HK G36 before that - the HK 417 makes use of a "pusher" rod-based gas system assembly over that of the traditional "hollow" gas cylinder common to conventional gas-operated assault systems. HK markets this feature as improved reliability over the life of the weapon as well as lower maintenance requirements and extended service life. During testing, the HK 417 and HK 416 have been put through their paces through the firing of thousands of rounds of ammunition. The overall project commitment has been in developing a weapon system with a supremely low rate of failure and - to date - it seems that HK has succeeded in that respect.
Outwardly, the HK 417 sports a fine clean and modern design look. The receiver is well laid out and constructed of both lightweight polymers and metals - a fine balance needed to produce a lightweight weapon that is also a manageable firing platform. The charging handle is set to the right side of the body as is the ejection port in typical HK fashion. The trigger unit is integrated to the lower receiver and attached to the pistol grip. The magazine feeds into a port just ahead of the trigger unit. The firing selector switch is located along both sides of the receiver making the weapon semi-ambidextrous. Firing modes include a safety, semi-automatic fire and full-automatic fire. The stock is tubular in its basic design and adjustable/collapsible, capped with a rubber pad for some comfort. The HK 417, like other modern rifle designs, makes use of Picatinny rail systems for the implementation of optics and accessories. A rail system is prominently featured across the top of the receiver and continued over the forend. The sides of the forend are also accessories-friendly. Another accessories rail is found under the forend which broadens the tactical applications of the HK 417. Iron sights are standard at the rear of the receiver and at the extreme end of the forend. Optics can quickly change the tactical nature of the HK 417 into that of a designated marksman's semi-automatic sniper rifle. The barrel protrudes ahead of the forend shroud and is capped by a slotted muzzle brake. The barrel is constructed of cold hammer forged steel and is chrome-lined for excessive wear and tear with conventional rifling therein. An optional single-shot grenade launcher can be affixed to the lower forend.
HK plans on eventually marketing their 417 in a variety of barrel lengths to fully broaden the customer interest base. The series intends to feature 12-, 16- and 20-inch barrel lengths which will turn the HK 417 from carbine to assault rifle to marksman rifle in minutes. The short form is known as the "Recce" while the basic form is the "Assaulter". The long form is the "Sniper". Additionally, only basic tools will be needed to change out the barrel assembly. The rail systems will also be easily removable and these without the need for tools or even "zeroing" the weapon after reinstallation of accessories.
To date, testing of the HK 417 has ensured zero-failure rates after some 15,000 rounds of ammunition were fired. Beyond consideration given by the United States military, the HK 417 is also tied to the militaries of Albania, Australia, Germany, Ireland, Malaysia, Netherlands, Norway, Poland, Portugal, Slovakia and the United Kingdom.