Steyr-Mannlicher STM-556 / Rheinmetall-Steyr RS-556 assault rifle


Steyr-Mannlicher STM-556 / Rheinmetall-Steyr RS-556 assault rifle


Steyr-Mannlicher STM-556 / Rheinmetall-Steyr RS-556 assault rifle with two quick-detachable barrels

Specification Value
Full text name Steyr-Mannlicher STM-556 / Rheinmetall-Steyr RS-556 assault rifle
Caliber cartridge 5.56x45 NATO, .223 Remington
Action type select-fire
Trigger type sa
Overall length, mm 960
Length, folded, mm 860
Barrel length, mm 406
Weight empty, kg 3,7
Magazine capacity, rounds 30
Cyclic rate of fire, rounds/min 600-800

STM-556 assault rifle was first introduced in 2012 by famous Austrian gun making company Steyr-Mannlicher. In 2016 it was announced that this rifle will be entered into Bundeswehr (German army) contest to replace HK G36 rifles now in service. To participate in this contest, Steyr-Mannlicher teamed with another famous military contractor, German-based Rheinmetall company, and their entry is designated RS-556 (as Rheinmetall-Steyr).

The STM-556 / RS-556 rifle represents an attempt to merge now-ubiquitous US M4 carbine ergonomics and layout with certain advanced features, borrowed from famous Steyr AUG-77 assault rifle.

Steyr-Mannlicher STM-556 / RheinmetallSteyr RS-556 assault rifle is based on US M4 carbine, using same basic layout with two-part receiver, made from aluminum alloy and connected by two cross-pins. All controls are also similar to M4,except that they are made fully ambidextrous. Key differences between STM-556 and standard M4 carbine lay in the gas system and barrel-receiver interface. The barrel on STM-556 is quick-detachable, with replacement system based on the proven Steyr AUG. Change of the barrel requires no tools and no disassembly, and takes less than a minute. The gas system is also based on the Steyr AUG, with manual gas regulator and short-stroke gas piston.

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