CMMG Banshee Mk17 9mm Pistol
Travis Pike for TTAG
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The CMMG Banshee Mk17 is a brand new entry into the Banshee pistol caliber carbine series, and no, it doesn’t take GLOCK magazines. It takes SIG P320 magazines.

The P320 has firmly cemented its place into the gun world by winning the Army’s MHS competition. It’s also being adopted across the country by police forces and seems to be popular in the civilian market, with even 80% Fire Control Groups being a thing. The Mk17 name is a reference to the M17, which is the military designation for the P320. 

The guns in the Banshee series are not just your everyday average PCCs or 9mm AR pistols. Most PCCs rely on a direct blowback system that leads to increased recoil. The Banshee uses a rotary delayed recoil system, eliminating the need for a heavy bolt, buffer, or spring.

The delay allows pressure to fall in the chamber before the bolt unlocks and allows the weapon to cycle. This system has proven to be quite robust and reliable, and the Banshee comes in various configurations to include .45 ACP and 10mm. 

Shiny little Fella (Travis Pike for TTAG)

The Banshee series also comes in three different series. Each series comes with various features and price points. The 100 series is the most basic model, the 200 Series has more features, and the 300 series is the premium model. The model reviewed in this article is the 300 series. 

300 Series Features

The most prominent feature is the titanium cerakote, but there are nine other color options. The pistol brace is CMMG’s modified SBA3 Ripbrace model. This brace allows you to set the position you prefer and then pull the brace instantly to that position every single time. 

The Cerakote and laser engraving is very well done (Travis Pike for TTAG)

We also get a QD port for a sling on the brace and a rear ambidextrous sling plate. The safety is also ambidextrous, as is the large charging handle.

Because the spring doesn’t need to be heavy and the charging handle is so large, the Banshee Mk17 is absurdly easy to rack and operate. The pistol grip is a Magpul MOE model, and the handguard is a free-floating M-LOK model with an integrated handstop. The barrel is also threaded so that you can add just about any can or muzzle device you want. 

Lastly, there’s a discreet laser-engraved logo that says Banshee on the right side near the magazine release lever.

The Banshee Mk17 Ergonomics

That magazine release is a rather ingenious idea. It’s massive and set rearwards to ensure the magazine is locked in place. You can quickly eject the magazine with nothing more than your trigger finger. It’s easy to depress and has almost no resistance behind it. 

The magazine release is very easy to reach (Travis Pike for TTAG)

The Ripbrace is fantastic and is quite stable and easy to use. It provides an excellent means of bracing the firearm and makes it quite handy. The ambidextrous charging handle and safety are nice touches, and I’ve come to appreciate the large charging handle and love the fact that it just glides rearward when used. 

The gun is quite light and weighs than 5 pounds. The low weight makes the Banshee Mk17 very handy, and the short 5-inch barrel makes it easy to maneuver. This makes it an excellent house gun, especially for someone who might not be strong enough for a proper rifle or shotgun. Also, many of us can carry in a read position in a vehicle with concealed career permits because it’s a handgun. In Florida, I can keep this loaded and accessible in my truck as long as it is considered securely encased. 

That thing is massive (Travis Pike for TTAG)

The short handguard gives you enough room to grip the gun, and if you choose, you can grasp the weapon by the magazine well and not lose much leverage. 

Range Time

That fancy rotary delayed blowback system does an excellent job of reducing the recoil commonly associated with blowback firearms. It has significantly less recoil than something like a CZ Scorpion, and the Banshee Mk17 weighs 2 pounds less than the Scorpion. As you’d imagine, the 9mm is a tame cartridge from such a big AR pistol, and muzzle rise isn’t an issue. 

The Banshee Mk17 is a kitten, and you can fire quite rapidly ad accurately into a target. This kind of gun is made for close-range use, and it’s a brilliant weapon within 50 yards or so. Past 50 yards, and we start to get some substantial bullet drop from the 9mm cartridge. Within 50 yards, the gun is also quite accurate. The trigger is a mil-spec model that’s not fancy, but its also not a bad trigger. Mil-Spec isn’t a universal descriptor for the trigger, and the CMMG model is a refined example. It has no pre-travel, and it’s just a wall, then a snap.  

So Short and So Light (Travis Pike for TTAG)

Accuracy wise you can generate a 2-inch group at 50 yards with nothing more than a red dot and a hasty prone position. At 25 yards, I saw groups smaller than an inch. That’s an excellent degree of accuracy from a 9mm subgun wannabe. It’s more than most will ever need. The Banshee Mk17 is a decisive weapon inside of 50 yards. 

I like to toss in wider varieties of ammo when I test a gun for reliability, but ammunition is not exactly easy to come by. I was stuck with a mixture of 115 grain SIG ammo, SIG M17 JHPs, and some classic 124 grain Winchester White Box loads. In the first 500 rounds, I was unable to make the gun choke. I even fired in a variety of weird ways, including a two-handed traditional pistol grip, one-handed, braced to my forearm, from the shoulder, and held outward in a quasi SAS style shooting position. 

CMMG Banshee Mk17 9mm Pistol

The Banshee never choked. It ate through it all without complaint or concern. The Banshee Mk17 is a ton of fun to shoot, and I want to spend a lot more time with the gun. 

Specifications: CMMG Banshee Mk17 Pistol

Caliber: 9mm
Barrel Length: 5 inches
Overall Length: 18.9 inches
Weight: 4 lbs 10 ounces
Capacity: 21
MSRP: $1,549.95 (300 Series model) 

Ratings (out of five stars):

Accuracy * * * *
As far as 9mm subguns go, this is one of the most accurate I’ve handled. It’s got a great trigger, and I find it an excellent and decisive firearm inside of 50 yards. 

Reliability * * * * *
It eats everything without any complaint. Shoot it in weird positions or normal ones…it won’t choke. 

Ergonomics * * * * 
The gun is light, handy, and the controls are mostly ambidextrous. The magazine release design is brilliant and the Banshee Mk17 makes the best of the AR-15’s ergonomics. 

Customization * * * * 
Like an AR-15, you can do almost anything you want to it. You can Barbie it up nearly any way you want. One star off because the rotary delayed system relies on CMMG parts that can’t be replaced by aftermarket options. At least not yet. 

Bang for Your Buck * * *
The Banshee Mk17 is an expensive firearm with an MSRP of $1,549.95, but it’s feature-filled and packed with excellent goods and handy add-ons. The 100 and 200 series are a good bit cheaper, too. The big downside is that the gun only comes with a single 21-round SIG P320 magazine. 

Overall * * * * 1/2
The Banshee is a very well made PCC that has a lot of refinement and a great overall design. It’s low recoiling, accurate, fun to shoot, and for P320 users, you have a premium grade option should you want a weapon that can share mags with your pistol. The Banshee Mk17 is a very capable weapon that’s a lot of fun to shoot. 


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    • Just because you’re an unemployed basement dweller who can’t afford to support himself doesn’t mean it’s trash….
      The price is meant to weed you filthy ghetto rats out….. in other words, you can’t afford it because you’re a loser lol

      • Just because you’re a butthurt boomer trying to spend the inheritance before your kids can get it doesn’t change the reason that this pistol is expensive af. It’s expensive because the production techniques used to manufacture the weapon employ increased hand fitting and custom work. The pricing has far more to do with gunsmiths taking the extra time to ensure outstanding fit and finish of the action and furniture than the manufacturer trying to cater to your wounded ego by weeding out filthy ghetto rats with a ridiculously high price, a bizarre fantasy that exists only in your pin-sized cerebrum.
        This thing has a niche and a well earned price tag, but that doesn’t make it the end all, and it certainly doesn’t mean that most of the PCCs under $1000 are significantly inferior. The banshee might present the user with an edge, but not enough to warrant the cost for anyone but those who use it for a living or who have more money than they know what to do with. Us “unemployed basement dwellers” who work twice the hours you do and are still barely scraping up money for rent, vehicles, etc. and cannot afford to throw away an extra grand on a whim are still plenty lethal with an Evo 3 or Sub 2000 that costs less than half the price lol

        • You prove by your words your own ignorance. I was born into a family with no money. I did not graduate from college, because there was no help and I had to pay my way from the age of 16…clothes, transportation, etc. I started a tiny little business in 1989 when I was 26 years old. And I have worked between 60 and 80 hours a week ever since.

          Yes, I now (finally) have some money to spend. And I can afford this gun if I choose to. But you have, and will never work twice the hours I do and your BS statements are ignorant. You have no idea what you are talking about, so you should just be quite and learn for a bit.

          Sorry if I seem irritated, but I am irritated by you and your obvious stupidity.

    • “A. Remove the forward assist, no need for it.”

      On FA configured AR uppers remove the guts and replace with an aftermarket delrin plug removing half the clutter and most of the excess weight.

      You’re welcome.

      • Seems like people with transferable lowers have be having reliability issues with them. Probably to many manufacturers of varying quality conversions to any sort of data set to conclude anything. Way 9mm is going now its not really worth ATM.

  1. What sense is there to buy this than put a brace on a pistol you already own? The barrel length is not long enough, red dots mean no sight radius increase, the pistol will weigh less than this AR, less clunky controls with the mag in grip… this is stupid.

    I gotta say that the reviews on here are seldom ever negative and it seems the guns with a higher MSRP get higher reviews than those with lower ones. Seriously, when’s the last time a gun that cost more than a grand got a bad review?

      • Doesn’t mean that they’re higher in practicality. This gun has no practical value and while it may have less recoil than a standard blowback PCC due to the design, the same can be said about locked breech pistols which can have a brace put on them.

        I know your goal is to review the guns as they are and leave competitive options out, but everything is relative and I don’t see how a $1500 pistol like this is a superior choice to a standard braced pistol at half the price, like say a Glock that uses the Roni Stab. Heck, with that setup you can take the Glock out of the Roni and carry it in a holster like a normal pistol. Very nifty and cheaper.

        • Cheaper yes, better, no.
          This is a gun for people who want a pistol caliber carbine, but want something that’s more refined than straight blowback. Given the number of guns in this niche (the Sig MPX, the MP5 clones, this gun, the lone wolf piston driven PCC, the Angstad Arms MDP-9) it’s obvious that the manufacturers think there’s a market. Given that they have continued offer PCC’s like this, and the designs are proliferating I think we can assume that there is a segment of the population that will happily buy them.

          I’m interested in getting a CMMG or the MPX. I have a straight blowback 9mm PCC and it’s okay. I intend to get a nicer PCC and sell that one. There’s nothing wrong with it, but I’d rather ride in a Lexus than a Ford Focus, and I’d rather have a PCC like the MPX or the CMMG than a straightblowback design. I’m willing to pay some extra for it. No one is forcing you to.

          Guns don’t HAVE to have a perfect practical purpose. You’re allowed to have fun. As for it’s usefulness in a homedefense scenario.. well it would sure beat throwing rocks. I imagine most who are purchasing this kind of firearm already have their bases covered as far as “go to war” or “defend the castle” firearms go.

        • De Facto, IF you read comment and had any critical reading skills you would see that my point wasn’t about blowback PCC’s, my comment was about pistols like Glocks, Sigs, FN’s, Walthers, etc. with an aftermarket brace installed on them. That would be a much more apples to apples comparison as none of those are blowback pistols.

          You seem focused on terms like “nicer” and “refined” but those terms have nothing to do with whether a gun is better than another. It may look better, it may feel better, it may make other guys at the range jelly, but until you’ve shot a braced Glock/Sig/FN/etc. and one of the “refined” non-blowback “PCC’s” side by side, you’re talking out of your ass in regards to them being better.

    • Your opinion is what’s worthless.. . Lol…
      You actually know NOTHING about practicality with firearms if you question the usefulness of this sub-gun……
      “Morons….gods special children”.

  2. can afford to use it in 9mm, actually useful in 10mm. .30carbine would be good. the fa does seem silly. oh to be in can country.

    • Might consider it in 7.62 Tok, or better. IF it had a couple of more inches on the barrel. e.g. 22 – 26 OAL, which is still plenty short for all but the tightest of tight quarter work. As is, it’s pretty well a less maneuverable large frame pistol. Albeit, more stable while firing.

      Don’t really see the point, outside of handicapped peeps.

  3. Glossy implement of wars untold can provide bonus certitude of disposition towards circular motion of vicious jackals, running the field, distressing objectives profoundly implied. Overseeing the lesson, “fiddle with it to discover.” Send them packing, quilting the fireworks!

    • i once received a text, “surname affect memory complaint delicacy lantern.”
      i replied, “intersection privilege remove border elevator moistness.”
      they did not respond.

      • Once reading a list of attributes on an imported kit of race parts. I shit thee not, it said on the packaging:

        “…it could getting stronger to resist and against crush.”

        Courtesy I suspect of 2002 – 2003 Google translate algorithm. But damn if it didn’t read like someone speaking while stroking out.

  4. Neat review. Thanks for the actual gun content.

    By chance, have you shot an Extar?

    More in my price range and takes Glock mags.

    I am not a Glock fanboy (43 and 48), but I think the best feature of Glocks is the magazine.

    Tough as nails and cheaper than most.

  5. So when does TTAG do a righteous review of CMMG hardware that isn’t pistol caliber or AR/AK clones?
    They have some very nice semi-auto rifles in calibers that make very respectable DMRs given the right glass.

  6. hypothetical scenario:
    kyle rittenhouse brings the banshee to kenosha instead of ar pattern carbine
    Q1 does he make it out of there alive
    its 2 am…
    theres 10 antifa/blm types making ready to bust through your front door…
    the police aint coming…
    your pregnant wife and 12 year old daughter are behind you
    do you want the banshee with a 21 round mag of 9mm
    or a 10.5 ar pistol with a 30 round mag of 5.56/.223/7.62×39
    food for thought: kenosha scanner on facebook reported multiple individuals in groups putting on soft body armor and other protective gear before hitting the streets to mostly peacefully protest
    Q2 in light of this and the almost total lack of availabilty/increasingly higher cost of 9mm is the banshee any longer a suitable weapon for self defense

        • Countless other responsible gun owners have managed to carry weapons at these sorts of events without shooting people.

          The first thing they taught me in Idaho’s Concealed Carry class is the grave responsibility involved in carrying a weapon. I’m not convinced that this kid understood that. I think he could have found a way to exercise his First Amendment rights without involving himself in a fatal altercation (with some admittedly stupid people).

          But again, I’ll leave it up to the jury.

        • Those countless gun owners you mentioned weren’t being attacked with improvised chemical weapons, having a firearm pointed at them, pursued by a crowd, kicked, hit with a skateboard to the head & shoulder either. Circumstances there were a bit more involved, and lethally, before the shooting than you’re making out.

          Perhaps you should watch the full videos and not spout off faux moral superiority when your position is nonexistent & wrong. I’m starting to think you’re being intentionally obtuse and posting to skew the narrative.

        • It’s best to stay away from stupid people doing stupid things at stupid hours of the day. That means keeping your distance from folks who violently disagree with you late at night.

          I suspect that the kid felt that his AR-15 gave him license to wade into the fray and “save people”. He said as much himself. That is a typical hero complex. He was also carrying illegally because he was underage.

          Weapons should not be used as an excuse for untrained folks to wade into the middle of a riot. Leave the hero stuff for the real heroes: Police and first responders.

        • Should’ve known, of course you’d come sneaking back in days later. Read the law yourself, because it states he was perfectly legal to be doing so, provided it was not a SBR or SBS, and he was not engaged in hunting without permits.

          As for the rest, you’ve earned a permanent disregard. Here’s a clue, not one of us cares what paid trolls like you post, except to shit can the trash you’re peddling.

        • I am not a paid troll. I am pro-Second Amendment fifth generation Idaho native. I am in favor of constitutional carry. I believe that responsible folks should be allowed to carry whatever weapons they want (short of nukes), but once they prove themselves to be irresponsible folk, those weapons should be taken away.

          The web page you cited is incorrect. Please study the actual law, which I have posted below.

          Section 750.234f

          Act 328 of 1931

          750.234f Possession of firearm by person less than 18 years of age; exceptions; violation as misdemeanor; penalty.
          Sec. 234f.

          (1) Except as provided in subsection (2), an individual less than 18 years of age shall not possess a firearm in public except under the direct supervision of an individual 18 years of age or older.
          (2) Subsection (1) does not apply to an individual less than 18 years of age who possesses a firearm in accordance with part 401 (wildlife conservation) of the natural resources and environmental protection act, Act No. 451 of the Public Acts of 1994, being sections 324.40101 to 324.40119 of the Michigan Compiled Laws, or part 435 (hunting and fishing licensing) of Act No. 451 of the Public Acts of 1994, being sections 324.43501 to 324.43561 of the Michigan Compiled Laws. However, an individual less than 18 years of age may possess a firearm without a hunting license while at, or going to or from, a recognized target range or trap or skeet shooting ground if, while going to or from the range or ground, the firearm is enclosed and securely fastened in a case or locked in the trunk of a motor vehicle.
          (3) An individual who violates this section is guilty of a misdemeanor, punishable by imprisonment for not more than 90 days, or a fine of not more than $100.00, or both.

          History: Add. 1990, Act 321, Eff. Mar. 28, 1991 ;– Am. 1992, Act 218, Imd. Eff. Oct. 13, 1992 ;– Am. 1996, Act 80, Imd. Eff. Feb. 27, 1996


          948.60  Possession of a dangerous weapon by a person under 18.

          Subsection(c) This section applies only to a person under 18 years of age who possesses or is armed with a rifle or a shotgun if the person is in violation of s. 941.28 or is not in compliance with ss. 29.304 and 29.593. This section applies only to an adult who transfers a firearm to a person under 18 years of age if the person under 18 years of age is not in compliance with ss. 29.304 and 29.593 or to an adult who is in violation of s. 941.28.

          History: 1987 a. 332; 1991 a. 18, 139; 1993 a. 98; 1995 a. 27, 77; 1997 a. 248; 2001 a. 109; 2005 a. 163; 2011 a. 35.
          Sub. (2) (b) does not set a standard for civil liability, and a violation of sub. (2) (b) does not constitute negligence per se. Logarto v. Gustafson, 998 F. Supp. 998 (1998).

          Emphasis in bold & italics is mine. That says you’re wrong.

          – 941.28 pertains to SBR/SBS weapons. Irrelevant here.

          – 29.304 refers to regulation of hunting by those under 16. Also not relevant.

          – 29.593 Licensing requirements for hunting. Same as above.


          Be advised, the DA has all the appearances of having grossly overcharged Kyle intentionally. Every attorney that has looked over the evidence thus far, including those who would have him strung up, like Eric Zorn, are firmly convinced he’s going to walk.

          You might ask yourself why they all think that. On the overcharging, it’s plainly obvious the prosecution is doing so to satisfy the rioting mob, and with a side motive to get Mr. Rittenhouse off the legal table, by preventing further malicious prosecution through double jeopardy prohibitions.

          If you aren’t doing an impersonation of Miner, and those paid trolls like him, forgive my assumption. There are loads of new names around here that are exactly that as part of disinformation & propaganda campaigns that are waged against this site and others like it, and you very much post exactly like the majority of them. If this isn’t the case, you have my apologies. But if my short hairs are accurate, and they quite often are, exceedingly…

      • Hmmmmmmmmmmmmmmmmmmmmmmm, it probably has to do with the fact that they were pointing a loaded gun in his face and attempting to bludgeon him with skateboards, doncha think?

    • I have a 9mm CCMG on order. But I split it up. I got the 300 lower and a 200 upper.
      The difference is the 300 series is all 5″ barrel lengths. The 200 series are 8″ barrels.
      I think the 300 series has your choice of colors baked in to the price. 200 serices cerakote (sp?) colors are extra.

      I bought this as a range toy/PDW host for my Octane 9HD can. Plus it’s got a high WAF. (Wife approval Factor)

  7. I just paid $1600 for a 300 MK17 pistol thinking it was a top shelf pistol. The first time I took it to the range, the trigger would not reset without fooling with the safety. Total trash. When I reached out to CMMG, they said it had defective parts and that they would would send replacements to me. Here is the message:

    I am very sorry to hear about this issue. That is not typical of a CMMG firearm out of the box. This problem occurs when machining marks are left on certain surfaces of the trigger disconnect and the hammer.

    The fix is easy and straightforward, it’s a simple matter of replacing the FCG. Could you please confirm your current mailing address? I’d be happy to send you the replacement.

    …So, this is like buying a car and finding out the motor does not work, but they will send parts….is it just me or is this crap for a $1600 gun? Unfortunately I am not an amateur gun smith, so I lack experience and tools. I might be able to replace the parts, but why should I? Any thoughts are appreciated.


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