Type Submachine gun Manufacturer SIG Sauer Weight 2.7 kg (6.1 lbs) | Place of origin USA Produced 2013 | |
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Variants MPX (Standard variant)
MPX-K (Compact variant)
MPX-P (Pistol variant)
MPX-PSB (Pistol variant)
MPX-SD (Integrally Suppressed Variant)
MPX-C (Carbine Variant) | ||
The SIG Sauer MPX is a gas-operated submachine gun primarily chambered in 9×19mm. It is the first submachine gun to feature a fully closed and rotating bolt and piston system. This is to enhance the safety of the user and make for a more reliable firearm. It was designed in 2013 and released to the general public in 2015. It features a SIG Sauer short stroke push-rod gas system to reduce recoil and improve the reliability of the weapon. The weapon, in its second generation, features a system that would allow for conversion from 9mm to .357 SIG or .40 S&W, however, since its inception, first party conversion kits have not been made available for either of the two production generations of the machine pistol.
Contents
SIG Sauer used the same gas piston system to develop the SIG Sauer MCX carbine.
Design details
The standard version of the MPX is the 9mm 8.0 inch (20.3 cm) version with a collapsible stock and free-floating rail. Barrel lengths vary from 4.5" to 16".
Features
The standard MPX submachine gun comes with a rear and front flip-up sight that is attached to the integrated rail system on the top of the weapon. One available modification is a SIG reflex sight mounted to the rail instead of the flip-up sights.
The MPX has a gas short stroke piston system in order to increase the accuracy of the weapon which operates in closed bolt. It is designed in this way to prevent water or dirt from entering the chamber and causing malfunctions as well as to use a silencer with greater ease. It features an ambidextrous selector switch for fully automatic (law enforcement/military models) and semi-automatic. It also features an ambidextrous bolt catch, and the weapons exterior appears to be a cross between an AR-15 and a Heckler & Koch MP5A3. The barrel is free-floating and is surrounded by Polymer/Steel Rail mounts.
The charging handle of the weapon is based on the AR-15 design at the back of the weapon. This is to ensure that cocking the weapon does not interfere with any optics mounted onto the Picatinny rail. The weapon's rails are made out of cast steel and the standard weapon overall weighs 2.1 kg. The semi-automatic version of the weapon can be registered as a Short-Barreled Rifle in most states in the U.S.
Variants list
MPX (Standard variant)
Standard submachinegun complete with a folding stock or a 3 position collapsible stock, 3 position fire selector and 8.0 inch barrel.
MPX-K (Compact variant)
Submachinegun with a 4.5 inch barrel.
MPX-P (Pistol variant)
Semi-automatic version with no stock and a 8.0 inch barrel.
MPX-PSB (Pistol variant)
Semi-automatic version with a SIG SBX pistol stabilizing brace and a 8.0 inch barrel. The BATFE has warned users of weapons using SIG stabilizing braces that shouldering a weapon fitted with a brace constitutes the making of a Title II NFA weapon, reversing a prior ruling that it did not.
MPX-SD (Integrally Suppressed Variant)
Standard Submachinegun with an MP5SD like Integral Suppressor and longer-fore-end. Barrel is 8.0 inches.
MPX-C (Carbine Variant)
Semi-automatic carbine version, featuring a 6.5 inch barrel with a 9.5 inch muzzle device permanently welded to it, which is actually a modified version of the baffle core of the integrally suppressed variant. SIG contended that this device was a muzzle brake, but in 2013 the BATFE ruled that the component was a suppressor, and classified the MPX-C as possessing an integral silencer and thus as a Title II NFA weapon. The BATFE rejected an appeal against this ruling in February 2014; SIG responded by filing a civil lawsuit against the BATFE, alleging they had acted in an "arbitrary and capricious manner." In September 2015, Federal Judge Paul Barbadora upheld the BATFE's ruling.
As a result of this SIG has announced a 16" barrelled carbine version without the suppressor.