FIRST LOOK: SOCOM's New Suppressed Upper Receiver Group

Matthew Moss
by Matthew Moss
SIG Sauer’s MCX-based SURG kit (via Soldier Systems Daily)

At the end of July, we reported that SIG Sauer had been awarded the $48 million contract to provide US SOCOM’s Suppressed Upper Receiver Group or SURG. At the time there was no confirmation of what form this new SURG took. SIG Sauer has since released a press release confirming their selection.

In the meantime, Soldier Systems Daily shared the first photo of what is reportedly the SURG. The photo is a little blurry but shows a piston-driven MCX upper receiver with detachable, rather than integral, suppressor. The FDE-coloured SURG kit will also reportedly provide the MCX’ folding stock too. As stipulated by the original SURG requirement the suppressor appears to be covered with a substantial mess wrap to protect user’s hands from burns.

Here’s SIG Sauer’s full press release detailing the selection of their SURG system:

NEWINGTON, N.H., (August 7, 2018) – U.S. Department of Defense (DoD) has announced the selection of the SIG SAUER MCX System for the Suppressed Upper Receiver Group (SURG) for the existing M4A1 Carbine. The SIG SAUER MCX SURG System will be an upgrade to the current M4A1 Carbine – a fully automatic version of the M4 Carbine – that went into service in 1994.

The DoD began the SURG program to upgrade, and optimize military weapons for continuous, suppressed use on the battlefield. The SIG SAUER MCX Rifle System outperformed the competition through the demanding, rigorous, and grueling testing to receive the SURG award. The SIG SAUER suppressor withstood the stringent stress and torture requirements set by DoD for firing specifications, vibration, sound, and temperature requirements to ensure soldier safety.

“The requirements set by DOD for the SURG procurement demanded significant improvements in reliability, thermal characteristics, and durability that went well above anything we are currently seeing in the industry,” said Ron Cohen, President and CEO of SIG SAUER, Inc. “We worked very hard to develop the MCX SURG System to specifically meet and exceed the DoD requirements. I am extremely proud that our hard work paid off, and endured the stringent and demanding military testing requirements, to ultimately gain the confidence of DoD to support their operations in the field.”

This DoD Award for the MCX SURG System is a $48 million, five-year, indefinite-delivery/indefinite quantity, firm-fixed-price contract with an expected completion date of July 2023. The system will be built at the state-of-the-art SIG SAUER worldwide headquarters in Newington, New Hampshire.

Sources: 1 2

Matthew Moss
Matthew Moss

Managing Editor: & Overt Matt is a British historian specialising in small arms development and military history. He has written several books and for a variety of publications in both the US and UK. Matt is also runs The Armourer's Bench, a video series on historically significant small arms. Here on TFB he covers product and current military small arms news. Reach Matt at:

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