The FourSix From CMMG – A New Banshee

CMMG seems to have a goal in chambering the AR-15 into every caliber possible. They’ve famously chambered the AR in standard calibers like 5.56, 300 Blackout, as well as 5.7×28, 10mm, and now 4.6x30mm. Lots of people complain that there is nothing new in the AR world, but the latest CMMG, the FourSix, is the first AR to chamber the 4.6x30mm round. In the United States, it’s seemingly the first civilian firearm to chamber the 4.6x30mm as well.

The 4.6x30mm is the other PDW round. It competed with the 5.7×28 in the early 2000s as part of the NATO PDW project. The 5.7 has the P90, and the 4.6 has the MP7. While FN released their 5.7×28 caliber guns to the civilian market, HK never did. Thus, the 4.6x30mm languished outside of the MP7. Until now anyway.

The FourSix joined the Banshee ranks as an AR pistol. I expected this to be a radial delayed firearm, but now, CMMG was able to make the FourSix a direct impingement gun. It uses a new micro-length gas system with a patent-pending micro gas block. It’s just an AR built to chamber the 4.6x30mm round.

Why 4.6x30mm?

Well, why not? The 4.6x30mm sits between a proper intermediate rifle round and pistol round. The FourSix and the 4.6x30mm can reach out to 150 yards and is relatively flat shooting at that range. It offers better penetration than a pistol caliber. The FourSix comes with an 8-inch barrel and keeps things compact without sacrificing much ballistic capability. You can point to the 300 Blackout for short-barreled power, but the 4.6x30mm packs less recoil, less muzzle rise, and a lighter platform overall.

The 4.6x30mm sits between the 5.56 and 9mm.

It fits the PDW round requirement and does so for the civilian market. These light calibers outperform pistol calibers in range and penetration but are lighter and pack less concussion and recoil when compared to a rifle round. Why the 4.6x30mm over the 5.7x28mm? Well, last time I looked, it’s cheaper, and the ammo is available at Midway.

Oh, and you guys remember when David Chapman, the gun grabber who was almost the head of the ATF? Well, the FourSix falls out of his definition of an assault rifle. He said it must be a .22 caliber projectile, and this is a centerfire .18 caliber projectile. I know we got rid of him, for now, but I think it’s funny.

From Front to Rear With the FourSix

The FourSix comes with an 8-inch barrel, topped with a CMMG SV muzzle brake. The gun comes with an ambidextrous safety, a massive CMMG charging handle, and a nice M-LOK handguard with enough room for an M LOK angled foregrip. Obviously, we get the RIpBrace system, which takes the SBA3 brace from SB Tactical and implements CMMG’s patented RipBrace system.

The CMMG SV Brake and M-LOK handguard are quite nice.

The FourSix weighs a light 5 pounds and 6 ounces. The overall length is 26.9 inches with the brace extended and 24.2 inches with the brace collapsed. CMMG threaded the muzzle with a 1/2x28mm thread pitch for easy suppressor use.

The RipBrace is back and easy to quickly deploy and use.

The lower isn’t a proprietary lower. Seriously, it’s your standard multi-cal lower. The reason we can use a multi-cal lower is that the FourSix uses a clever magazine design. The magazines are roughly the exact dimensions as an AR-15 magazine and will fit any standard Multi-Cal AR lower. The FourSix will be sold as both a complete gun and a separate upper for you to turn any AR pistol or SBR into a 4.6x30mm compatible weapon.

The magazine fits the dimensions of a standard Mil-Spec magwell.

That magazine holds forty rounds of 4.6x30mm and will fit in any standard AR-15 magazine pouch. Not bad by any means, and the magazines even engage a typical last-round bolt open device. It’s simple but effective and intelligent.

The FourSix has an MSRP of $1399, and the magazines have a retail price of $39.99.

Going Ping, Pew, and Pow with the FourSix

CMMG sent me both the gun and ammo because, well, the ammo is admittedly expensive. With 400 rounds of 4.6x30mm, I hit the ground running. I quickly installed a red dot on the gun, zeroed it, and went nuts. From the start, the FourSix proved to be absurdly easy to shoot and control.

Shooting the FourSix is a blast.

Recoil and muzzle rise is barely noticeable. Controlling the weapon with rapid strings of fire is insanely easy. The dot barely moves between shots, and my long strings of fire group together like a tight shotgun pattern.

The FourSix delivers hardly any recoil

That’s the real strength of this weapon. It’s easy to control, and it’s lightweight and super easy to handle quickly and accurately. It feels like a loud 22 Magnum but hits harder and penetrates deeper. Double taps, triple taps, strings of fire moving beyond five rounds are all very easy to control and keep on target at 15, 25, and 50 yards.

It’s also stupid accurate and easy handling.

My drills under time were super fast, with me scoring some serious personal bests on drills like the VTAC 1-5, which involves 15 rounds fired into the A-Zone of three targets rapidly. My fastest time was 3.57 seconds. It’s not the Kyle Lamb fast, but I feel good about it.

At 100 Yards

The Banshee FourSix also proved to be quite accurate at 100 yards. The bullet drop is barely noticeable, and if I aim for the chest, I hit the chest. No need to compensate like crazy for drop like I would with a 9mm. Plus, due to the lack of any actual recoil or muzzle rise, you can make decently quick and accurate shots at this range.

It’s ready to drop on, drop in, and shoot.

In a supported kneeling position, I sent five 40 grain FMJ rounds at 1,900 feet per second at a 10-inch steel gong in five-second with all hits. The Mil-Spec trigger isn’t fancy, but it’s a crisp single-stage design that doesn’t leave me with many complaints. It’s not fancy, but it gets the job done. Since it’s a standard AR, you can clean it up with a drop-in trigger easily enough.

Little, Loud, and Mean

The FourSix’s controllability makes it a capable defensive weapon. This makes it easy to see why the SEALs love the MP7 for close-quarters fighting. The FourSix delivers unto you a soft shooting, easy-to-control weapon perfectly suited for new shooters and those who might find a real rifle heavy and cumbersome. Plus, the gun worked through all 400 rounds without any issues. The magazines work perfectly and provide enough firepower to make any home defender feel well-armed.

40 rounds of 4.6x30mm will make it easy to deter an attacker.

Need is a loaded term, and people asking why you need this simply fail to have any imagination. You might not need it, but the 2nd Amendment isn’t about needs. A civilian 4.6x30mm PDW is a win for the world of firearms. I’m a huge fan of having choices, and I see every new choice as a win. Plus, the FourSix proved to be an accurate, controllable, and well-made weapon.

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  • Anna August 17, 2022, 8:32 am

    I can’t say I’m impressed by them using a full size AR lower. They made the same mistake with the 5.7 version. Part of the beauty of the PDW cartridges is the reduced size of the gun but also the magazine.

    Anything using a 556 size mag might as well benefit from a 556 cartridge; otherwise I’m struggling to see the virtues. This is sort of like taking a F350 pickup to a custom shop in order to have a motorcycle engine installed.

  • Tony Gajak August 16, 2022, 10:58 am

    It’s like a 22 mag.

    • Anna August 17, 2022, 1:21 pm

      NO it’s NOT! It’s nothing like a 22mag unless you’re comparing pistol cartridges to hot dogs; otherwise it’s just bad science to say the two are “like” each other.

      • Pantexan August 20, 2022, 9:05 am

        Hmmm……the author says it feels like a .22 magnum. So it must be something like a .22 magnum.

  • Nicholas August 15, 2022, 9:59 am

    Instead of spending money on bringing actual winning cases to the courts based on what the Constitution actually commands, the firearms industry spends money on duping people into spending more money on a choice that is not going to protect future generations from the never ending onslaught on our rights.
    The entire industry, and that includes those who write articles on all the new “stuff” are no friends of the right/duty to keep and bear arms.
    The U.S. and State Constitution’s require an armed citizenry with statutory powers. Why is it that there are no articles being presented that educate the so-called pro-2nd community on the proper enforcement of the Duty that would prevent much of what has taken place to reduce all our rights?

  • Winters August 15, 2022, 9:37 am

    So, a bullet the same diameter as a BB in a $1400 pistol? Thanks, but I’ll stick with my 5.7×28!

    • Pantexan August 20, 2022, 9:16 am

      Yes! I would feel so much better using a .22 caliber bullet (5.7 mm).
      A BB is smaller than 4.6 mm (4.3 to 4.4 mm).

  • survivor50 August 15, 2022, 8:44 am

    REALLY ??? Another Caliber in an AR ???

    I’ll wait for the 3.3 X 13 with a 3 in barrel …

    ” COME ON MAN ” !!!

  • Chuck Cochran August 15, 2022, 7:07 am

    Dagnabit Travis! Now you’ve made me want one. On a retiree’s budget, that’s going to take a while, especially with Bidenomics. I might manage to save up in time for 2024.

    • Hondo August 25, 2022, 7:49 am

      2024 is not looking good Chuck, poopy Joe decided we need to pay deadbeats student loans, this dementia ridden imbecile couldn’t be fast enough.

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