CMMG Releases Mk4 3GR “3-Gun Rifle”

Not content with only 12 rifles in their Mk4 product line, CMMG has announced the release of the 3GR “3-Gun Rifle.” It comes standard with a 18″ stainless steel barrel, CMMG’s excellent RKM14 keymod handguard. and a Geissele SSA trigger.

TTAG has had a moment with the rifle. It seems that the Muzzle Break is a bit too compensating… We will reach out to CMMG for our own evaluation.



The 3GR retails for $1,399.95, a bargain taking into account purchasing each component individually. 

  • Caliber: 5.56mm
  • Barrel: 18” medium weight taper profile
  • Muzzle: CMMG SV brake, threaded 1/2-28
  • Hand Guard: CMMG RKM14 KeyMod hand guard
  • Furniture: Magpul MOE pistol grip, MOE rifle butt stock
  • Receiver: Forged 7075-T6 AL M4 type upper, AR15 type lower
  • Trigger: Geissele Automatics SSA
  • Weight: 7 lbs (unloaded)
  • Length: 38”


Nathan S

One of TFB’s resident Jarheads, Nathan now works within the firearms industry. A consecutive Marine rifle and pistol expert, he enjoys local 3-gun, NFA, gunsmithing, MSR’s, & high-speed gear. Nathan has traveled to over 30 countries working with US DoD & foreign MoDs.

The above post is my opinion and does not reflect the views of any company or organization.


  • ARL

    Too bad you broke the muzzle.

  • TheSmellofNapalm

    This may be irrational to many, but that streamlined stock combined with the grip, keymod guard and flattop upper make this an extremely attractive gun to me, aesthetically speaking. I just really like how it looks.

    • Gene

      Agreed. Seems like the lines and whatnot are a discriminant. It is an attractive piece.

  • Esh325

    Could it be the muzzle break working too well or perhaps it is the way he’s holding it? If the later is true then perhaps he could take a more relaxed stance? If leaning back causes you to loose control of the gun and make the muzzle rise in normal situations, wouldn’t leaning more backwards with a overly compensated muzzle brake help the gun muzzle stay on target more?

    • I would initially be skeptical too, but Mr. Leghorn is on FN’s Shooting Team. I have met him before and know he can handle a rifle.

      While we cannot see the top of the break, my guess is that they made the port(s) facing up too large/efficient.

      • Nick Oosh

        Apparently the side effect off too-large ports is smirking smugly. Ugh. Who let the fratboy with the unpoppped collar on the range?

  • ronnie raygun

    that’s weird – I was just sitting here thinking “What this world needs more than anything is another AR rifle”

  • Lance

    like always way overpriced for a AR.

  • Scott Edvin

    CMMG really have interesting features. Gunlovers really
    enjoyed tos hoot from these guns


    MA Firearms Safety Course

  • echelon

    I have one of those Magpul MOE fixed rifle stocks on my 6.5 Grendel hunting AR and I gotta tell you…I think I like it better than the collapsible stocks. It’s very streamlined and comfy and has a nice LOP.

  • ColaBox

    Wow TTAG did a gun review? Certainly unlike them.