Steyr-Mannlicher STM556

History of the Steyr-Mannlicher STM556

The STM-556 assault rifle was first introduced in 2012 by renowned Austrian gunsmith Steyr-Mannlicher. It was announced in 2016 that the rifle would enter the Bundeswehr competition to replace the then-in-service HK G36 rifle.

To participate in this competition, Steyr-Mannlicher cooperated with Rheinmetall, another well-known military company. Your entry explicitly specifies RS-556 (for Rheinmetall-Steyr).

The STM-556/RS-556 rifles represent an attempt to combine the ergonomics and layout of the now ubiquitous American M4 carbine with some of the other advances of their own famous Steyr AUG-77 assault rifle function combined.

As such, this weapon uses the same basic layout as the M4 carbine, with a two-piece receiver made of aluminum alloy and connected by two cross pins. The controls are also similar to the M4, except in this case they are fully ambidextrous.

The main difference between the STM-556 and the standard M4 carbine is the gas system and barrel receiver interface. The barrel of the STM-556 is quick detachable with an exchange system based on the proven Steyr AUG.

Replacing the barrel requires no tools or disassembly and takes less than a minute. The gas system is also based on the Steyr AUG with a manual gas regulator with a short stroke gas piston.

Specification

BASICS

Year of Service

2012

Origins

Austria

Categories

Assault Rifle/Assault Carbine

Manufacturer

Steyr-Mannlicher - Austria / Rheinmetall - Germany

Operator

Austria; USA

Roles

Auto function

Has mechanical features to automate the firing process.

Assault Rifle

A modern class of long guns with selected fire characteristics, automatic internals and magazine feeding.

Dimensions and Weight

Overall Length

850mm

33. 46 inches

Barrel length

370mm

14. 57 inches

Cured weight

6.33 lbs

2.87 kg

Attractions

Front and rear irons; optional optics

Action

Selective fire; gas powered

Gas Power

proposes a pneumatic system that typically consists of a cylinder and a rear drive piston that directs power to the bolt assembly.

Cartridges and Paper Feeds

Caliber*

5. 56x45mm NATO

Circle/Feed

Removable 30-round magazine

POWER

Maximum efficiency. Arrived

1,650 feet

(503m | 550m)

Rate of fire

900

Number of revolutions

Mile speed

2,900 ft/s

(884m/s)

VARIANTS

STM556 - Name of the basic series RS556 - Assault rifle form offered by German Rheinmetall and Steyr-Mannlicher; variable barrel length; 4. 2kg weight; adjustable optical axis; standard and optional Optional accessory rail bracket.