The HK417 is a German battle rifle designed and manufactured by Heckler & Koch. It is essentially a enlarged version of the HK416 chambered in 7.62x51mm NATO for use as a designated marksman rifle, or just about any scenario where the superior penetrative qualities and terminal ballistics of the 7.62mm round proves useful.
The HK417 is identical in internal design to the HK416; however, the receiver and working parts have been enlarged to accommodate the larger 7.62mm round. It uses a bolt similar to that of the AR-10 derivatives, but it uses the short-stroke piston operation (which means it has an actuator rod). Early models were fed from G3 compatible magazines which could not hold the bolt open, requiring the user to chamber the first round of every magazine manually. Later, a magazine resembling the plastic one used by the G36 was created featuring a bolt-hold open design. The 50-round drum magazine of the HK21E machine gun is compatible with the HK417 for the fire support role.