SIG Sauer SIG516


The SIG Sauer SIG516 is an assault rifle and a semi automatic rifle manufactured by SIG Sauer, chambered in 5.56×45mm NATO.

History

The SIG Sauer SIG516 shares lineage with the Heckler & Koch HK416. The principal firearms engineers for the SIG516 were Robert Hirt and Chris Sirois. Following his time with Heckler & Koch, Hirt was recruited by SIG Sauer to work with then SIG engineer Chris Sirois on an improved version of the HK416. The SIG516 omitted many proprietary HK416 components that were exchanged for standard components. Other HK416 issues like the high cyclic rate, which causes lower life cycle, a gas vent, which showed up in low light conditions, and safety issues were also addressed. Hirt and Sirois later designed the SIG716 and SIG MCX/SIG MPX. They were later recruited by Caracal to develop the CAR 816 series.

Design details

Operating mechanism

The SIG516 is a multi-caliber assault rifle capable of selective fire. It fires from a closed bolt, and it has a short-stroke push rod piston system. The gas piston pushes the bolt carrier rearward where it is returned to the forward and locked position by a spring. This process loads the next cartridge. The 516 has a four-position gas regulator, allowing the user to choose the amount of gas directed to the piston, to adjust the gas system to function reliably with various propellant, projectile, fouling, operating environment, and configuration-specific pressure behavior.

Features

The SIG516 is based on the AR-15 platform ergonomic architecture, but it uses a short-stroke gas piston operating system. The SIG516 uses a proprietary bolt carrier and government rifles a special tungsten granules containing buffer to manage bolt carrier bounce and soften recoil. The barrel is chrome-lined. The amount of movement between the upper and lower receiver is minimized by a rubber wedge.
The SIG516 has a safety lever on the left side to be used by the thumb of the shooting hand. The gas block integrates an adjustable gas regulator. The front gas block is railed to accept the front sight with a flip-up sight post. SIG516 models are equipped with an M16A2 style bird-cage flash hider.
All SIG516 models except the Marksman are equipped with barrels shrouded by a free-floating M1913 Picatinny rail, as well as flip-up iron sights made by SIG Sauer.
The 5.56×45mm NATO SIG516 models accept STANAG box magazines. These magazines are constructed in 5-, 10-, 20-, and 30-round variants. SIG516 Russian rifles use a different magazine as they are chambered in 7.62×39mm. The SIG516 Russian uses magazines designed for 7.62×39mm AR-15 style rifles. The rifle is hammer-fired and has a two-stage trigger mechanism in the SIG516 Marksman while all others have a military specification single-stage trigger.
It is built to pass the NATO test protocol "Over the Beach", meaning the SIG516 is designed to fire safely as quickly as possible after being submerged in water.

Variants

SIG516 Precision Marksman

The SIG516 Precision Marksman has a longer barrel and an adjustable stock. It weighs and has a length of. The barrel is chrome-lined. Iron and or optical sights are installed on an integral MIL-STD-1913 Picatinny rail on the top of the receiver and additional accessories can be mounted on the fore end quad rails.

SIG716

The SIG716 is a battle rifle variant, which is based on the same design, but is chambered for the larger 7.62x51mm NATO round and uses SR-25 pattern magazines.

SIG716 G2

The SIG716 G2 variant features a short-stroke pushrod gas system. This operating system reduces carbon fouling, excessive heat and unburned powder in the action, ensuring further improved reliability and function. The G2 Patrol model is chambered in 7.62×51mm NATO, while the G2 DMR model is chambered in 6.5mm Creedmoor.

SIG 716i

The 716i variant features a gas-operated, rotating bolt system instead of short-stroke pushrod gas system. This Stoner bolt and carrier piston operating system has helped SIG Sauer to bring down the cost of manufacturing and pushing more sales of 716i, whilst also achieving a weight reduction. The 716i is chambered in 7.62×51mm NATO. Sig Sauer appears to have discontinued SIG716 and SIG716 G2 models, since the company stopped displaying these products in their website, while they continue to sell magazines and spare parts in their online store. The 716i has been recognized as the best AR-10 rifle for the year 2020, by readers' choice voting of Ballistic magazine.

Users