In this post, we’re comparing popular short-barrel 9mm AR pistols (AR9, MP5, and unique designs) – SIG MPX K, Springfield Kuna, CZ Scorpion 3+, CMMG Banshee, Century Arms AP5, and the Daniel Defense PCC.
SIG SAUER MPX K
- Barrel Length: 4.5 inches
- Platform: Proprietary
- System of Operation: Short-stroke gas piston, closed bolt
- Controls: Fully ambidextrous
- Magazine Type: Proprietary MPX magazines (35rd)
- Suppressor host: Good
Springfield Armory Kuna
- Barrel Length: 6.125 inches
- Platform: Proprietary
- System of Operation: Roller-delayed blowback
- Controls: Fully ambidextrous
- Magazine Type: Proprietary (translucent 30rd mag with steel feed lips)
- Suppressor host: Excellent
CZ Scorpion 3+ Micro
- Barrel Length: 4.2 inches
- Platform: CZ Scorpion
- System of Operation: Blowback
- Controls: Fully ambidextrous
- Magazine Type: CZ Scorpion mags (backward-compatible)
- Suppression: OK
CMMG Banshee MkGs
- Barrel Length: 5 inches
- Platform: AR9
- System of Operation: Radial Delayed Blowback
- Controls: AR-style controls with ambidextrous safety selector
- Magazine Type: Glock-pattern mags
- Suppressor host: Excellent
Century Arms AP5-P
- Barrel Length: 5.75 inches
- Platform: MP5 clone
- System of Operation: Roller-delayed blowback
- Controls: Standard MP5-style controls
- Magazine Type: MP5-pattern 30rd mag
- Suppression: Excellent
Daniel Defense PCC
- Barrel Length: 8.3 inches
- Platform: AR9
- System of Operation: Direct blowback with hydraulic buffer
- Controls: Fully ambidextrous
- Magazine Type: CZ Scorpion mags
- Suppression: OK
Recoil and Feel
The biggest divide here is between the operating systems: direct blowback vs. delayed systems. But first let’s talk about the MPX K – it’s often talked about like it’s in a class of its own. It’s built around the short-stroke piston system, so it doesn’t have that heavy, clunky bolt slamming back and forth like you get with blowback guns. It’s flat, fast, and stays exactly where you point it. Some even say it feels like shooting a .22. If you want to run fast drills or compete, this is one of the best options you have.
Right on its heels – and arguably sweeter for some – are MP5 clones, like the Century Arms AP5. Thanks to the roller-delayed blowback action, the AP5 gives you buttery-smooth recoil impulse.
The Kuna brings that same roller-delayed action to a more modern, affordable package. It might have a tiny bit more kick than a true-blue MP5, but it’s still miles ahead of any direct blowback gun.
The CMMG Banshee uses its own unique “Radial Delayed Blowback” hybrid system. It’s another soft shooter that does a great job taming recoil. When it’s tuned right (often with specific buffers), it rivals the MP5 for softness.
Then you have the CZ Scorpion 3+ and the Daniel Defense PCC. These are direct blowback, meaning a heavy bolt and spring are doing all the work. Physics dictates they will have more “thump.” The Scorpion is known for being snappy. The DD PCC manages it better thanks to good engineering, but you will definitely feel more movement compared to the delayed guns.
SIG SAUER MPX K
$1,999.99
Price accurate at time of writing
- Caliber: 9mm
- Barrel length: 4.5"
- Capacity: 35rd
- Weight: 5 lbs
Trigger
The SIG Sauer MPX K comes with a Timney trigger from the factory, and people absolutely love it. It’s light, crisp, with almost no take-up and a reset you can barely feel. It’s pretty much perfect out of the box.
The Banshee and Kuna also get high marks for their factory triggers. They’re clean, light, and a huge step up from your standard mil-spec affair. Most owners feel no need to upgrade them, which is a big win for your wallet.
The Scorpion 3+ trigger is probably its weakest point. It’s heavy and a bit gritty. It’s functional, but nearly everyone agrees that an HB Industries spring kit is an almost mandatory (and thankfully cheap) first upgrade.
The AP5 trigger is solid for a military-style gun. It’s functional and reliable, though not something you’d call a “match” trigger. It does the job well. The Daniel Defense PCC comes with a mil-spec trigger that, while reliable, might feel gritty and heavy. On the bright side, it takes standard AR-15 triggers, so you can easily drop in your favorite Geissele or LaRue.
CMMG Banshee MkGs
$1,464.99
Price accurate at time of writing
- Caliber: 9mm
- Barrel length: 5"
- Capacity: 33rd
- Weight: 4.9 lbs
Reliability
The Daniel Defense is solid. Runs hard and fast. However, it can be picky about magazines – it loves Magpul sticks but sometimes chokes on CZ Scorpion mags.
Thanks to its simple blowback design, the Scorpion 3+ isn’t picky about ammo at all. There were some concerns about bolt deformation on older models, but it seems to be a rare issue. Most owners have zero problems.
The MPX K is very reliable, though fully loaded 30-round magazines can sometimes be hard to seat on a closed bolt. Downloading them by one round usually solves it.
The AP5 is reliable if you respect the break-in. The manual says to run 500 rounds of 124gr NATO spec ammo first. Do that, and replace the extractor spring with a genuine HK one, and it’ll run forever.
The Kuna is solid mechanically, but being a newer platform, it had some early teething issues with proprietary magazines (cracked feed lips). Third-party mags are fixing this.
The CMMG Banshee is generally reliable, but earlier generations had issues with ejector springs wearing out prematurely. The newest versions seem to have addressed this.
CENTURY ARMS AP5-P
$1,499.99
Price accurate at time of writing
- Caliber: 9mm
- Barrel length: 5.75"
- Capacity: 30rd
- Weight: 5.5 lbs
Ergonomics and Controls
If you know how to run an AR-15, you already know how to run the MPX K, Daniel Defense PCC, and CMMG Banshee. They all feature identical manual-of-arms: safety selector, magazine release, and bolt catch are exactly where your muscle memory expects them to be. The Daniel Defense gets bonus points for fully ambidextrous controls.
The Springfield Kuna also mimics the AR layout, making it very intuitive. It features a reversible charging handle and ambi controls. The safety selector is incredibly stiff out of the box. Some people like the positive click; others find it annoying to manipulate quickly.
The CZ Scorpion 3+ has vastly improved ergonomics over earlier generations. The grip angle is better, and the mag release is now AR-style (button) rather than paddle. However, the safety selector can still dig into your trigger finger knuckle.
The AP5 is… well, it’s 1960s German engineering. There is no last-round bolt hold open, so reloads are slower. The charging handle is forward on the left. It’s cool (everyone loves the “HK slap”), but it’s slower and less intuitive than modern controls. The safety selector can be a reach.
CZ SCORPION 3+ Micro
$1,279.99
Price accurate at time of writing
- Caliber: 9mm
- Barrel length: 4.2"
- Capacity: 20rd
- Weight: 4.7 lbs
Customization & Compatibility
The AR9 pistols – CMMG Banshee and Daniel Defense PCC – are the clear winners here. Because they are essentially AR-15s, you can swap grips, stocks, triggers, and safety selectors with thousands of aftermarket parts. You can build them exactly how you want without needing specialized parts. The CMMG Banshee feeds from Glock mags, which is a huge plus.
While the MPX K does share a few parts with a standard AR15 ( triggers, grips, and some controls/charging handles), most of the gun is proprietary and AR parts will not drop in. The platform has good aftermarket support, but parts are expensive. Thanks to its modularity, you can swap barrels and handguards easily, which is a huge plus.
The CZ Scorpion has a massive aftermarket following. You can change literally every part of the gun, but you’ll be buying Scorpion-specific parts. It’s easy to customize, just not “AR-15 easy.”
The AP5 has decent support, but MP5 parts are expensive. Mounting optics can be a pain. You usually need a claw mount. Handguards are swappable, but it’s not as modular as the modern options.
The Springfield Kuna is the new kid on the block, so its aftermarket is still growing. For now, you’re mostly limited to what comes in the box, aside from standard rail accessories, and you’re stuck with proprietary magazines.
DANIEL DEFENSE PCC
$1,949.00
Price accurate at time of writing
- Caliber: 9mm
- Barrel length: 8.3"
- Capacity: 30rd
- Weight: 5.9 lbs
Suppression Performance
A huge reason to get a 9mm PCC is to run it suppressed.
The AP5 and Kuna are naturally great hosts. The roller-delay keeps the action closed longer, meaning less noise at the ear and less gas in your face. The Banshee’s radial delay also helps with port pop.
The SIG MPX K also suppresses well, but its gas piston system can result in some “piston pop” and more gas to the face compared to the delayed-blowback guns. Aftermarket adjustable gas blocks can help tune the system for suppressor use. The tapered barrel can cause alignment issues with cheap adapters. Use a quality mount or direct thread.
The Daniel Defense PCC and CZ Scorpion suppress okay, but because the bolt opens relatively fast, you get more “port pop” (noise at the ear) and gas blowback than the delayed systems.
Verdict:
Buy the Century Arms AP5 if:
- You want the softest shooting experience possible.
- You want the best suppressor host.
- Nostalgia is a drug and you need that Die Hard aesthetic.
- Trade-off: outdated ergonomics and no last-round bolt hold open.
Buy the SIG MPX K if:
- You want the best performance in a modern package.
- You want AR controls with near-MP5 smoothness.
- You have a higher budget and don’t mind paying for expensive magazines.
- Trade-off: It can be gassy when suppressed.
Buy the CMMG Banshee if:
- You want a great middle ground – soft shooting but with AR controls.
- You want to use Glock magazines (most Banshee models accept them).
- Trade-off: It’s not quite as proven as the MPX or MP5.
Buy the CZ Scorpion if:
- You are on a budget but want a reliable gun.
- You love tinkering and customizing your gear.
- Trade-off: It has harsh recoil compared to the others and needs upgrades out of the box.
Buy the Daniel Defense PCC if:
- You want a “buy once, cry once” reliable rifle that needs zero tinkering.
- You want standard AR parts compatibility.
- Trade-off: You are paying $2,000 for a blowback technology.
Buy the Springfield Kuna if:
- You want something compact and different.
- You want roller-delayed tech without the HK price tag (or ergonomics).
- Trade-off: It’s new and lacks rail space.
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