Staff Writer (Updated: 8/29/2016):
Outwardly, the HK416 looks the part of the M16 assault rifle of its smaller cousin, the M4 Carbine. The pistol grip, trigger group and magazine feed are all contained under the main body of the weapon. The feed system can take on the M16-style STANAG magazine of 20- or -30 rounds as well as a 100-round Beta C-Mag drum). The magazine release catch is located along the upper right rear of the magazine housing while a the fire-selector lever is along along the left side of the lower receiver (fire modes represented as a pictogram). The weapon fires the 5.56x45mm NATO cartridge and the firing action is of gas-operation with a rotating bolt. A rate-of-fire of 700- to 900-rounds per minute is possible (of course this is ammunition type- and barrel length-dependent). The barrel is free-floating and made to fire upwards of 20,000 rounds before needing replacement. In fact, publicized videos show the gunsmiths at Heckler & Koch testing HK416s through some 10,000 rounds of ammunition on full automatic fire without the system ever jamming. The bolt itself stays cool to the touch, allowing the operator to handling the component with bare hands without injury. Sight fixtures include a rear rotary diopter type and a front post. The HK416 is set to take on the MIL-STD-1913 Picatinny modular rail system so it can utilize the same enhancements and accessories as the M16 and M4. A foregrip can be installed ahead of the magazine feed. The stock is collapsible and extendable as needed. The HK416 can fire out of the water with no ill effects to performance.
One of the benefits of the HK416 lies in its new gas system developed from the one used in the Heckler & Koch G36 assault rifle. The HK416 makes use of a short-stroke piston driving a rod that moves the bolt to the rear. This contained action reduces heat build up along the bolt carrier group and keeps gasses from making their way into the internal workings of the gun. The end result is a reliable and long-firing weapon system worthy of military hands. The short-stroke, gas-piston system is contrary to the direct impingement system used in the base M16 rifle. The new system is said to increase the life of the internal workings of the weapon while at the same time cutting down on malfunctions during in-the-field firing.