CMMG Mk17 Banshee Review: A PCC that takes Sig P320 Mags
CMMG released the new Mk17 in both the Resolute and Banshee lines of rifles and pistols. The Mk17 uses Sig Sauer P320 magazines instead of Glock magazines. We had a chance to use the MK17 Banshee for a few weeks and it ran flawlessly.
Today we are reviewing is the pistol version of the Mk17 Banshee in the 200 series. If you aren’t familiar with the CMMG product line, they offer 100, 200, and 300 series of both the Banshee and Resolute. There are some differences between the series that will determine what version you want to go with, but they share several features as well.
P320 Magazines
The thing that is unique about the CMMG Mk17 Banshee versus previous versions is the use of Sig P320 magazines. Typically, when a new pistol caliber carbine (PCC) is introduced, the first thing people want to know is, “Does it take Glock mags?” While the decision to switch to the Sig P320 magazines might seem odd, there are some very good reasons to do so.
With the U.S. Army and Marine Corps adopting the Sig Sauer M17/M18 handguns, a new wave of buyers experienced with the P320 entered the market. Historically, military veterans purchase the firearms that they used while in service. With this in mind, the CMMG Mk17 makes sense. Not to mention that the Sig P320 in all of its variations is the top-selling handgun of 2020.
Radial Delay Blowback
CMMG created the Radial Delayed Blowback (RDB) system from the ground up to eliminate problems with traditional blowback systems affecting pistol caliber AR15’s. The biggest advantage of the RDB system is a gun that weighs less while simultaneously having less felt recoil.
With a traditional blowback system, the only thing keeping the chamber closed is the weight of the bolt and the action spring tension. As a result, the more powerful the cartridge, the more weight is necessary to keep the bolt closed long enough for safe operation. With the RDB system, the bolt is forced to rotate and unlock itself before it will cycle. This slows things down enough for chamber pressures to drop to safe levels ensuring reliable and safe operation without the need for heavy bolts or stiff action springs.
Mk17 Variations
As mentioned earlier, there are several versions of the CMMG Mk17 Banshee. In fact, there are currently six in total: three pistols and three short-barreled rifles (SBR). Every version features a billet lower and forged upper. Additionally, all versions feature a CMMG RML7 M-Lok handguard, mil-spec trigger, bolt release, and extended mag release. As with the other Banshee models, it features the last round hold open on an empty mag.
The 100 series features mil-spec hardware. The pistol grip and safety are standard-issue. In the pistol version, it will have a plain pistol buffer tube. The SBR version has an M4-style buttstock. The receivers and handguard are hard coat anodized. This is the entry-level for the Mk17.
The 200 series, like the version we are reviewing, steps things up a Magpul MOE pistol grip. A CMMG SV Brake replaces the standard flash hider. Lastly, the CMMG Fastback 6 position enhanced receiver extension and the Ambi sling plate finish the upgrades. For the pistol version, an SB Tactical brace is included, and on the SBR you get the very cool CMMG RipStock. Cerakote is available for $150 extra in both the 100 and 200 series.
Finally, the 300 series is the top of the line offering from CMMG. Featuring all the same upgrades from the 200 series with the addition of an oversized Ambi charging handle, Ambi safety, Cerakoted receivers, dust cover, and handguard. The 300 series is available in 10 different colors at no additional cost.
Which is Best for You?
This will be up to the individual’s preferences, but overall we think the 200 series is a good place to start. If you look at just the stock upgrades, it is more than the $200 difference between the 100 and 200 series. Add in the Magpul grip and upgraded brake then the value is even more apparent.
Stepping up to the 300 series makes sense if you want a full Cerakote gun or a shorter barrel. The price for Cerakote on the 200 series is an additional $150 which brings you up to the same price point as the 300 series. You could look at the addition of the oversized Ambi charging handle, Ambi safety, and Magul vertical grip (on the SBR) as free add ons.
Each CMMG Mk17 Banshee ships with one 21-round magazine and a retail price ranging from $1,199.95 to $1,549.95 for the Banshee and $1,299.95 to $1,799.95 for the Resolute (depending on series).
Key Features: CMMG MK17 Banshee
CALIBER: 9×19
BARREL: 8″, 1:10 twist, Medium Taper, 4140CM, SBN
MUZZLE: CMMG SV Brake, threaded 1/2-28
RECEIVER: Forged 7075-T6 AL M4 type upper, Forged 7075-T6 AL Lower
HANDGUARD: CMMG RML7 M-Lok handguard
FINISH: Hard Coat Anodized Receivers and Hand Guard (Can be upgraded to Cerakote)
CHARGING HANDLE: CMMG Mil-Spec
PISTOL GRIP: Magpul MOE
PISTOL BRACE: CMMG Standard RipBrace with 6 Position Fastback Receiver Extension and Ambi Sling Plate
TRIGGER: CMMG Single stage mil-spec style trigger
TRIGGER GUARD: Integrated Into Lower
SAFETY SELECTOR: CMMG Mil-Spec
MAGAZINE: P320 21rd
WEIGHT: 5lbs 12oz(unloaded)
LENGTH: 24.4″(brace collapsed)
MSRP: $1,199.95 – $1,549.95
Jeremy Mallette is co-founder of International Sportsman. An avid hunter and outdoorsman, he has spent more than a decade in the outdoor industry, from hiking and camping to silencers and hunting. His father taught him to shoot at age six, and he received his first firearm at age eight — a 1942 Colt Commando .38 special revolver. He enjoys yearly trips to Kansas for pheasant hunting, spending time with his children at the deer lease, and collecting unique firearms.
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