Heckler &amp; Koch HK417Heckler &amp; Koch HK417 Heckler & Koch HK417 The Heckler & Koch HK417 is a battle rifle and designated marksman rifle. It is designed and manufactured by Heckler & Koch in Germany. Being the larger caliber version of the Heckler & Koch HK416, and chambered for the 7.62×51mm NATO rifle cartridge, it is intended for use where the penetrative power, stopping power, and range of the 5.56×45mm NATO HK416 would otherwise be insufficient. The HK417 is gas-operated, has a rotating bolt and is capable of selective fire. The HK417 has been adopted for service by a number of armed forces, special forces, and police organizations  throughout the world, including the "Bundeswehr", United States Joint Special Operations Command, the United States Army, Russian Spetsnaz forces such as FSB Alpha Group, and others. Design and features. The HK417 is similar in internal design to the HK416, although the receiver and working parts are enlarged to suit the larger 7.62×51mm cartridge. The bolt is a seven-lug rotating type, which sits in a bolt carrier and operates in a forged alloy receiver resembling those of the Stoner-designed AR-10, AR-15 and M16 rifles. Like the HK416, the HK417 is gas-operated with a short-stroke piston design  similar to that of the Heckler & Koch G36. The short-stroke piston may be more reliable than the original direct impingement operation of the AR-15 design because, unlike these weapons, it does not vent propellant gases directly into the receiver, which deposits carbon fouling onto the bolt mechanism as well as heating it up. The early HK417 prototype used 20-round magazines from the Heckler & Koch G3 rifle family, which did not feature a bolt hold-open device. Later prototypes, however, switched to a polymer magazine with bolt hold-open. The magazine resembles an enlarged version of the G36's  transparent magazine, except without the pins for holding more than one magazine together. Use. Purchasers of the HK417 have typically intended it to complement lighter assault rifles chambered for less powerful intermediate cartridges (often 5.56×45mm NATO), for the designated marksman role. The HK417's greater accuracy, effective range, and penetration offset its greater expense, its lower rate of fire, and its smaller ammunition capacity both in magazine and carriage. Variants. Military and law enforcement. The HK417 models chambered for 7.62×51mm NATO available to the military and law enforcement market are: Improved model. The HK417A2 is an improved version . The design of the receiver, barrel interface, gas port and the bore axis alignment of the rifle have been further optimised to increase its accuracy and reliability. The German Army uses the HK417 A2 - 13″ with the designation G27. As of 2013, the HK417A2 models chambered for 7.62×51mm NATO available to the military and law enforcement market are: Accurized barrels provide 0.3 mil (1 moa) accuracy (with match grade ammunition). A barrel can be changed in under two minutes with simple tools. All HK417 barrels are cold hammer forged and chrome-lined and use a conventional lands and grooves  bore profile with a twist rate of 1 turn in . They are designed to function reliably with bullet weights ranging from and are threaded for a flash hider or sound suppressor. G28. After using the HK417 as a stopgap designated marksman rifle under the G27 designation, the civilian MR308 was used to develop the G28, a designated marksman rifle for the German Bundeswehr ("Federal Army") deployment to the War in Afghanistan. The semi-automatic G28 is chambered for 7.62×51mm NATO and has a factory warrantied accuracy of 45 mm dispersion at 100 meters (0.45 mil or 1.5 moa) when  fired with 10 rounds using OTM/HPBT/Sierra Match King ammunition. The G28 features STANAG 4694 NATO Accessory Rails that are backwards-compatible with the STANAG 2324/MIL-STD-1913 Picatinny rails. The upper receiver is made from steel instead of HK's aluminium alloy. Approximately 75% of the parts are interchangeable with the HK417. There are two different versions of the G28: G28 E2 (Standard) with a Schmidt & Bender 3–20×50 PM II (modified to Bundeswehr requirements) and the G28 E3 (Patrol) with Schmidt & Bender 1–8×24 PM II. By October 2017, Heckler & Koch had renamed the G28 as the HK241, though  G28 remains its Bundeswehr designation. M110A1/M110E1. In April 2016 Heckler & Koch confirmed that a lighter version of the G28 had won the United States Army's Compact Semi-Automatic Sniper System contract to replace the M110 Semi-Automatic Sniper System. It is designated as the M110A1 and uses an aluminum upper receiver instead of steel to meet weight requirements, weighing unloaded and reaching some loaded and with accessories; the M110A1 features a Geissele M-LOK rail handguard, Schmidt & Bender 3–20×50 PM II Ultra Short telescopic sight, Geissele optic mount, OSS SRM6 suppressor, 6-9 Harris bipod and mount, and  a collapsible stock with adjustable comb. In May 2018, the U.S. Marine Corps will begin receiving the CSASS, also to replace the M110. In March 2018, the Army announced that a version of the G28E-110 would be issued to infantry squads as the service's standard Squad Designated Marksman Rifle (SDMR). It has been designated as the M110E1. Issuing a 7.62×51mm NATO SDMR is meant to increase individual squads' ability to defeat enemy body armor that standard 5.56×45mm NATO rounds cannot penetrate. The M110E1 will replace the M14 EBR, in use by the Army since 2009, but  because it was based on an operational needs statement it had to be turned in by units at the end of a combat deployment. Unlike the sniper configuration, the SDMR model will be equipped with a different buttstock and barrel twist than the CSASS model. The marksman version is fitted with a simpler SIG TANGO6 1-6×24 telescopic sight to make quick adjustments between , and it fires M80A1 Enhanced Performance Rounds or XM1158 Advanced Armor Piercing Rounds rather than sniper rounds; it will be fielded with a suppressor to make the marksman less identifiable with louder 7.62×51mm NATO rounds . The SDMR TANGO6 1-6×24 telescopic sight features a red horseshoe dot for fast aiming and an illuminated Extended Range Bullet Drop Compensation (BDC) illuminated front focal plane reticle. Roughly 6,000 are planned to be fielded with one per squad in infantry, engineer and scout formations. U.S. Army combat units began receiving the first M110E1 SDMRs in April 2020. Fielding to all close combat squads is expected to be completed in late 2023. Civilian. The MR308 is a civilian variant of the HK417, introduced in 2007 alongside the MR223, a civilian HK416. It is a semi-automatic rifle with several  sporterized features. At the 2009 SHOT Show, the two rifles were introduced to the American civilian market as the MR762 and MR556, respectively. Since then, both were replaced by the improved MR762A1 and MR556A1. Heckler & Koch HK417 The Heckler & Koch HK417 is a battle rifle and designated marksman rifle. It is designed and manufactured by Heckler & Koch in Germany. Being the larger caliber version of the Heckler & Koch HK416, and chambered for the 7.62×51mm NATO rifle cartridge, it is intended for use where the penetrative power, stopping power, and range of the 5.56×45mm NATO HK416 would otherwise be