The CMMG Mk3
CMMG’s website lists a variety of Mk3 rifles from four different lines. I’m a big fan of the Dissent line, which uses a buffer inside the upper receiver so that you no longer need a buffer tube. This opens the doors to a bunch of new stock options.
The Banshee line is mostly pistol and SBR-type personal defense firearms with shorter barrel lengths and appropriate accessories. The Resolute line offers rifle lengths and accessories for longer engagements. Lastly, the Endeavor rifles feature more of a marksman configuration built for long-range work.
Related Review: CMMG Banshee Mk4 – Screaming Good Fun in .300 Blackout
There is an Mk3 version of all these rifles, but my test rifle is a slightly older Mk3 that came out before these more modern lines from CMMG. While still based on the CMMG Mk3 receiver set, this rifle features different furniture and handguard.
Shooting the CMMG Mk3
I wanted to see what this rifle was capable of, so I put a US Optics TXH 3-18x50 riflescope on it using a ZRO Delta cantilever scope mount. The 3-18 would do well shooting targets at relatively close distances, and with a max of 18X, it would also be suitable for distances at the end of the .308 Winchester’s envelope.
I grabbed some PPU 150-grain ball ammo and some 175-grain DTM match, plus a small tripod with a saddle to support the rifle for precision shooting. I also wanted to see how the rifle fared as a suppressor host, so I packed my YHM R9 suppressor. It has never done me wrong when testing .308-chambered rifles.
With rifle and gear, I headed to one of my shooting spots in the canyons near my home. We set up a bit of a range with targets from 50 to 200 yards. After zeroing the rifle at 100 yards, I fired a few groups to see how it patterned. Once satisfied, we switched to shooting a few transitions and some simple reload drills.
The significant power of the .308 is a little bit more to handle than your typical 5.56 carbine, and the added weight of the rifle was certainly noticeable. Both features turned into assets once I went prone and set the rifle on the tripod. The added power of the .308 helped with spotting impacts at 400-500 yards, as did the weight of the rifle by mitigating recoil so I could see the shots.
Ergonomics
It’s hard to complain about AR ergonomics, especially when they are so easy to change. The adjustable stock made it easy to tune the rifle to fit me, and the rest of the gun lined up as it should.
I would also mention that CMMG’s more recent products have even better build quality, with lighter and more comfortable parts. The only things I might complain about are also user-changeable, so they’re probably not even worth mentioning. I will say that it sure seemed heavy for what it is, but I guess I am just used to doing the same thing with far less gun.
Reliability & Accuracy
For the most part, the Mk3 was reliable – after a bit of a lube, anyhow. Testing used guns can often bring the previous owner’s faults to the surface, and this gun hadn’t seen a proper cleaning in a while. Plus, being bone dry in sub-freezing temperatures wasn’t optimal for function. But with a little elbow grease and some lube, it was fine.
I did have a couple of failures to eject, but I am confident that was based on the rifle’s condition when it came to me. Once it was serviced, it never skipped a beat.
I don’t know why, but I was expecting the rifle to shoot a little better than it did. Five-shot groups with match ammunition were typically around 1-2 MOA, which isn’t terrible, but I had a feeling the rifle would do much better if given the chance. Perhaps it would fare better after a good bore cleaning and with some additional ammo testing.
I didn’t have the opportunity to run a bore scope through this rifle, but in my experience, CMMG barrels shoot well. So, it’s also possible that this barrel had been a bit abused.
Value
Since this is an older version of the Mk3, it’s hard to evaluate value. It’s not a fair representation of the current Mk3 offerings, which I believe are better than this one. A comparable current production Mk3 from CMMG will likely run around $1,900.
That price tag puts it above the category of brands like Rock River and Smith & Wesson but still cheaper than Daniel Defense or Patriot Ordnance Factory. That's good company to keep, in my opinion. It seems once you cross the $2,000 point, things seem to improve. You can certainly pay more for other guns than you would for a CMMG Mk3 and get less performance.
Pros & Cons
I’ve already mentioned that the gun feels heavy for what it is, but unfortunately that is the case with many AR-10-type rifles. The KeyMod handguard is a bit dated as well – I don’t even have any KeyMod-compatible accessories left to attach to it.
Again, CMMG’s current production Mk3s have significantly better features like improved charging handles, triggers, and other controls. I have several new CMMGs that prove the company has stepped up its game significantly. Upgraded handguards and furniture are coupled with handsome Cerakote finishes and M-LOK handguards, while features like CMMG’s muzzle devices also improve the look and performance.
I really like AR-type rifles when they are short and sweet, which is probably why I found the Mk3 to be ungainly. I guess you simply have to go into .308-sized ARs with that in mind. I have yet to pick one up and think, “Oh, this is definitely easy and pleasant to move around.”
Something about the weight and balance of these guns requires additional effort to shoot, but that’s simply something to factor in if you want an AR-type rifle with this kind of power.
Final Thoughts
After shooting many different CMMG rifles at this point, it’s hard to avoid becoming a fan boy. I like the company's new offerings, though they come with a steep (but justifiable) price tag.
This older rifle may be somewhat less desirable than its contemporary siblings, but I would be very happy with the modern version of this rifle, the Resolute Mk3. Perhaps we’ll look at it next.
