Marine Raider Regiment Declines the M27

I’m a big fan of the AR-15 platform and of HK’s version, the 416, which became the USMC’s M27 IAR. The USMC really like the M27, and has moved it from being the squad automatic weapon to also being the squad designated marksman’s weapon, and soon to being the standard weapon for every man in the fireteam. But the Marine Raider Regiment has declined to get in on that, saying they’re happy with their existing M4s. Let’s unpack this a little bit. I’ve long held that while the HK 416 is a good weapon, it doesn’t do much that a well set up M4 doesn’t.

The Marine Raider Regiment1 is a special forces offshoot of the Marine Corps. So it’s under the auspices of SOCOM, not the regular Marine Corps. In terms of equipment, it gets to pick from it’s choice of stuff that SOCOM approves of and stuff from its parent service branch (i.e. the USMC). Previously, the carbine choice would be between USMC-standard M16A4s and M4s or the SOCOM M4s. Being a smaller group with a much greater ability to get new stuff, SOCOM has nicer M4s than the USMC does. Or Big Army for that matter.

M4s configured through SOCOM channels will probably have the following features: safe/semiautomatic/full automatic trigger group instead of the safe/semiautomatic/burst trigger group, a medium-weight barrel profile instead of the “government” barrel profile, and a longer, free float handguard. For the handguard, it will likely be either the Daniel Defense M4 RIS II quadrail2 or one of Geissele’s Mlok handguards.3 Either way, that’s most of what you get in a 416, other than the short-stroke gas piston system. At best, this would be a lateral move, to a new weapon system that doesn’t get you much else4, and is heavier to boot.

The M27 is also a little bit longer (16″ barrel on the M27, instead of a 14.5″ barrel on an M4A1). Which doesn’t sound like much, until you add a suppressor. And the Marine Raiders always run suppressors. Adding the suppressor length gets you back to the approximate barrel length of the M16. Longer is a little more awkward indoors, and the Raiders have mentioned that as another reason why they like their M4A1s.

None of this is all that surprising to me, but it’s always nice to see someone else confirm one’s analysis.


  1. f.k.a. MARSOC. 
  2. I discussed this rail in more detail in my M4 PIP post
  3. Discussed here
  4. In my post comparing the M4A1 PIP and the HK416, I talked a bit about how long each weapon can sustain a cyclic rate of fire. 

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