Springfield Armory KUNA: A Modern Roller-Delayed 9mm Carbine for a Grand? Shut Up and Take Our Money

We first got word of the HS Produkt Kuna on a factory visit to Croatia, just before the world lost its collective marbles due to a Chinese lab leak. Since then, the design has been refined, and Springfield has added it to their considerable list of SKUs, importing it for the general public as a large format handgun. 

Why then, should you consider this particular wannabe subgun, versus anything else out there? Glad you asked.

SPECS: HS Produkt, imported by Springfield Armory Kuna

• Caliber: 9mm Luger
• Capacity: 30 rounds
• Barrel length: 6 inches
• Overall length (as pictured, stock folded): 19 inches
• Weight (as pictured): 7.1 pounds
• MSRP: $1,000 to $1,150

UNDER THE HOOD

There are essentially three operating systems available to the end user, when looking at the 9mm carbine scene. The most basic — straight blowback — has the advantage of being inexpensive to manufacture, but comes with the downside of a heavy bolt and more recoil than the 9mm Luger cartridge has any right to generate. 

Gas piston operation is a comparative rarity, exemplified by SIG’s MPX line, but it sacrifices simplicity for low reciprocating mass. Then, there are the various flavors of roller-delayed carbines, ranging from the iconic MP5 and its clones, to newcomers such as Angstadt Arms’ UDP9 and the Stribog. 

The Kuna uses a version of the roller-delayed blowback system, but it’s a clean-sheet design incorporating a lot of refinements. 

Rather than start with a rifle-caliber carbine and then adapt it to a pistol cartridge like most AR-15 designs, the Kuna is wrapped around a magwell dimensioned for the 9mm and 40 S&W. 

Why the latter, which has largely slipped into the collective memory hole? Because certain South American police forces still have a fondness for it, and there’s a whole lot of them. Casting a jaundiced eye at the area immediately in front of the mag catch, there appears to be more than enough space to accommodate the extra 4mm length of a 10mm versus 40 S&W round, and the operating stroke is also plenty long enough. 

Don’t be too surprised too if there’s a line extension in the future, just to service the shouty nerds in the comments section who whine for a 10mm version, then purchase enough for all of their friends — i.e., zero. It’s easy to go bust in the gun biz listening to your customers. 

The Kuna’s magazines are a proprietary, double column, two-position feed design and appear both well thought out and executed with curved, translucent polymer bodies and reinforced steel feed lips. 

Unlike SIG’s MPX mags, these don’t appear to have been lovingly crafted from gossamer spun by elves and blessed by the Pope himself, so you won’t need a second mortgage in order to stock up. We’d like to see a 20-round version for use in messenger bags and backpacks, but as it stands, the two 30 rounders that ship with the gun are a good start. 

All controls can be operated with either hand, including the bolt hold open, and the bolt release is positioned so that it can be hit with either the index finger of the master hand, or the support thumb during a reload. 

As this is a European design, the safety can be engaged regardless of whether the hammer is cocked, and the levers fall naturally under the thumb. Sweeping the safety off is easy, but we found it’s better to use the trigger finger’s knuckle to reapply it. Shooters are never happy with their purchase, and most will find some way to make it their own; one of the quickest and easiest mods is to switch in your favorite pistol grip. 

In this case, the process is simplified by using an AR-15 fitment, so unscrew the bolt and Bob’s your uncle. The one that comes from the factory has the same texture as the Echelon handgun and is fairly vertical. 

The polymer lower is attached to the aluminum upper by means of two captive takedown pins, the rear of which locks the Pic-railed endcap in place. Field stripping is as simple as it gets. Push out the pins and remove the lower. Slide the endcap downward about a ¼ inch and pull it free. Then, use the charging handle to slide out the recoil spring, bolt, and carrier. That’s about as far as you’ll need to go to keep the gun running — hose it off with brake cleaner, then spray everything with oil — but further disassembly isn’t at all complicated. 

Fire control components are unique to the Kuna, though the hammer, trigger, and disconnector will look familiar to AR owners, and like the MP5, they’re held inside a chassis to form a trigger pack, which can be removed by first pulling out the safety selectors. 

Critical components are silver and appear to be nickel boron coated for wear resistance and lubricity. Our sample started out with a 6-pound single-stage trigger with some creep, but as time and bearing surfaces worn on, it worked its way down to 5.2 pounds, and more of a rollover feel — there’s enough bearing surface to work with, should anyone want to attempt a trigger job.

The Kuna’s serialized upper receiver starts out as an aluminum extrusion. Its full length Picatinny top rail provides a recess for some of the best backup iron sights we’ve seen on a subgun, though, when folded, they’re a bit too low to use with a stock that’s been set up for optics. 

Once flipped up, they’re more than usable, and provide both windage and elevation adjustment. The folding, non-reciprocating charging handle can be swapped without tools from left to right side, and there’s a replaceable, fixed ejector bolted to the receiver wall, opposite the ejection port. 

The bolt is where things get interesting. It’s a serious chunk of steel, tipping the scales at over 19 ounces (as compared to a 9mm AR, which typically weigh in at around 22 to 25 ounces for carrier and buffer). In order to cram everything into a small space, the gun relies not on a powerful recoil spring, but a single roller at the 12 o’clock position, which locks the bolt to the barrel trunnion when in battery. 

There’s a separate, spring-loaded weight forward of the main bolt and at rest, the spring pushes the weight forward, camming the roller into engagement. On firing, recoil compresses the spring, allowing the weight to travel about 3/16 of an inch to the rear, freeing up the roller and unlocking the bolt. At the end of its stroke, the bolt runs into a squishy polymer buffer, cushioning its impact. 

Due to being designed around the 40 S&W cartridge, we’d be interested in playing around with lightening the bolt and seeing what that did to both recoil impulse and bolt speed — there’s certainly plenty of steel available to mill out.

OUTFITTING THE KUNA

One of the first things we did to our sample Kuna, even before sending the first rounds downrange, was to file a Form 1 and turn it into a legal short-barreled rifle. That done, it was time to replace the Strike Industries folding brace it arrived with and add a stock, because while braces are a useful thumb in the eye to the ATF, they’re not as useful as a proper stock. 

In keeping with its compact nature, we chose an A3 Industries folder, which offers a solid lockup and adjustments for both length of pull and comb height. From the same company came a handstop and stubby vertical foregrip, and an M-LOK panel to insulate the right side of the handguard area. 

The left side received a remote pressure switch, wired to a SureFire Turbo Mini Scout light, while aiming was handled by means of a Trijicon MRO. A Dead Air Mojave 9 rounded out the ensemble, replacing the factory muzzle brake.

ROUNDS DOWNRANGE

We shot the Kuna initially with its muzzle brake installed, thinking that, while cute, it probably wasn’t going to have much of an effect. 9mm Luger simply doesn’t have the gas volume 

or pressure to work a comp very effectively compared to a centerfire rifle round, and on a 5-pound carbine, the effects would be negligible. It wasn’t until we started pushing the pace, firing multiple double taps on B/C-sized steel, that we noticed the dot was actually being pushed down on recoil, then would jiggle to the right as the action cycled. 

Investigating further, the Mojave 9 was installed. The dot still jumped downward slightly, but it never left the confines of the target at 40 yards, allowing for some of the fastest, most consistent hammers we’ve seen on a subgun-sized carbine. 

In terms of recoil impulse, the closest we can recall is an MP7, which doesn’t recoil so much as vibrate, courtesy of its tiny projectile. If you can press the trigger without disturbing your sight picture, the Kuna will keep pace with full-sized guns like the MP5 when it comes to speed and placing multiple rounds on target. Unlike the MP5, this has ambi controls placed where a normal human can reach them, a bolt hold open, and a magwell that doesn’t require the accuracy of a laser-guided anti-tank weapon to hit. 

Its fixed, hammer-forged barrel proved to be capable of the kind of accuracy you’d expect, and we had no trouble shooting 2-inch groups at 50 yards with both S&B 124-grain ball and Federal Hydrashock Deep.

In conclusion, this seems like another winner from HS Produkt. If you’re looking for a compact and effective backpack or vehicle gun, the Kuna delivers a lot of controllable firepower in a very compact package that’s easy to shoot well. Those in the market for a PDW would be well advised to consider it, as would anyone looking for a fun recreational shooter that would perform in PCC matches. 

It’s initially offered in two models, one with a Strike Industries brace and one without for 150 bucks less, which by happy coincidence is almost the cost of a tax stamp …