Heckler & Koch HK417
The HK 417 is an up-scaled version of the HK 416, designed to chamber the 7.62x51mm NATO (.308 Winchester) round. Like the 416, the 417 is a gas-operated, short-stroke piston design, which has been acknowledged to be more reliable than the original direct impingement operation of the AR-10 design. The early prototype HK 417 utilized 20-round magazines from the H&K 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 is similar to the G36 series transparent magazine, except without the pins for holding more than one magazine together.
The HK 417 is designed more for use as a "designated marksman" rifle than an assault rifle, with its increased cost, accuracy, and decreased rate of fire and magazine capacity.
The HK 417 comes in three main variants (all in 7.62x51mm NATO):
- HK 417 12" 'Assaulter' Model
- HK 417 16" 'Recce' Model
- HK 417 20" 'Sniper' Model