USMC NOT Evaluating Accessories for M27 Upgrade

Matthew Moss
by Matthew Moss
USMC evaluating accessories for M27

It has been suggested that the US Marine Corps’ Weapons Training Battalion at the Quantico Marine Corps Base is currently evaluating accessories for the M27 Infantry Automatic Rifle. The reality, however, is that the M27s, recently ordered by the Corps, will be identical to their first batches of rifles ordered back in 2007.

Soldier Systems Daily recently shared a photograph which is reportedly several months old. The three
weapon configurations in the photograph were assumed to be potential future configurations for the Marine Corps’ M27 IAR under evaluation as the Corps nears the impending wider fielding of the M27.

According to Solider Systems Daily the Corps examined the Upper Receiver Group – Improved (or URG-I) and this technology demonstration variant was considered as a potential alternative to additional M27s before this idea was actively killed. Currently the Corps’ M27 are fitted with a heavy quad Picatinny rail forend – basically the same as that introduced with the HK416 fifteen years ago.

The forends in the photo appear to come from Geissele with the Super Modular Rail HK on the left and the others appear to be MK16s – all in Desert Dirt Color, or DDC. The rifle on the far right has Magpul rail covers attached. The centre rifle has Geissele’s High Speed Selector, which in theory enables faster engagement time by having a selector which can be pushed forward to full more quickly, to engage fleeting targets within 150M.The first rifle appears to have a TangoDown Battlegrip, while the others retain the traditional pistol grip. The rifles are also fitted with Vortex Razor II 1-6 optics and BE Meyers MAWL-DA lasers. All the rifles pictured are equipped with B5 Systems Enhanced SopMod stocks. The configurations appear to have been assembled by individuals who are aware of current end-user requirements.

Marine with M27 during a live-fire weapons exercise, 2017 (USMC)

A source has confirmed to TFB, however, that the Marine Corps is not actively looking at accessory improvements for the M27 and that the photo was taken during a third party test at a private range for the benefit, but not at the request of, the Corps. The source advised that while one of the range day’s primary aims was to highlight the inadequacy of the stock HK rail system in meeting the USMC’s basic night time engagement criteria and readiness standard and encourage the Marine Corps to look at the available improvements which could be made to the rifle. Another element to the test was the evaluation of the tracking and zero retention of the Vortex Razor II 1-6, the Leupold 3-18 Mk6, and the Nightforce 4-16 ATACR.

The testing sought to find what the furthest distance an 8 inch target could be hit given pure mechanical accuracy of the weapons, in multiple positions, and using various means of support using an IR aiming laser at night. Our source noted that the URG-I gave the best performance, able to reliably hit the target at a range of about 130M, the upgraded HK416 reliably hitting the target out to about 126M and the stock HK416 was only able to strike the target with 100% consistency at approximately 95M with no return to zero for the sight due to the loose rail fit and the rail’s single attachment bolt essentially acting as a fulcrum.

The 8 inch target was used on the basis of representing realistic target sizes such as the brainstem and heart, plus the tolerance provided by the terminal ballistic behaviour of modern rifle bullets. The concept is that a rifle, ammunition and sighting system must be mechanically capable of achieving immediate incapacitating effects.

The Marine Corps will be purchasing around 8,000 more M27s over the next year or so. However, new accessories will not come as standard with the new rifles. A USMC spokesperson confirmed to us that their was no immediate timeframe at the moment for the evaluation of new accessories for the M27. It seems that the Corps’ expedited decision to purchase more M27s without further formal testing of other options is leading to a loss of potential performance for Marine riflemen in the field.

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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