Zenith Z-5 is a perfect semiautomatic rendition of the original MP5
Produced in Turkey on licensed HK machinery, Zenith Z-5 is a perfect semiautomatic rendition of the original MP5. Installation of a sliding stock requires BATF registration as a Short-Barreled Rifle, but resulting gun is fast, maneuverable, and has a high “cool factor.”


The submachine gun was birthed in the blood and filth of World War I as a compact combat tool optimized for trench clearing. Typical infantry rifles were cumbersome bolt-action monsters that could reach out past a kilometer and serve double duty as a proper pike with a bayonet attached. But when the engagement distance was close enough to smell what your opponent had for breakfast that morning, something handier and faster was needed.

The Italian Villar Perosa was technically the first, but the German MP18 really defined the genre. Short, handy, and feeding from a complex 32-round snail drum magazine, the 9mm MP18 fired about 500 rounds per minute and gave WWI German Stormtroopers a decisive tactical advantage. Suddenly everybody on the planet had to have submachine guns.

SIG MPX pistol equipped with their Pistol Stabilizing Brace
SIG MPX pistol equipped with their Pistol Stabilizing Brace brings all that is awesome about the submachine gun to American consumers without the burden of a transfer tax.

By World War II, submachine guns were in their ascendancy. American forces were saddled with the badly obsolete Thompson, a design that is iconic and effective, but nonetheless as heavy as a boat anchor. The subsequent M3 Grease Gun and the British Sten were cheap, fairly reliable, and easily mass produced. The German MP40 personified these same attributes with a bit more refinement. But the German StG44 Sturmgewehr assault rifle portended the eventual demise of pistol-caliber subguns.

Here our tale takes an interesting turn. Despite the widespread adoption of smaller-caliber combat rifles, the Israelis introduced the 9mm Uzi in 1954 and with it helped secure a new Jewish nation. The Uzi was built like a farm implement and, while heavy, was nigh indestructible.

In 1964, the German firm Heckler & Koch adapted the roller-delayed action from the wartime MG42 belt-fed machine gun to a pistol-caliber platform and devised the seminal MP5. This magnificent piece of en-gineering was as smooth as a sewing machine while setting new standards for accuracy in the platform.

SIG Pistol Stabilizing Brace
Revolutionary SIG Pistol Stabilizing Brace catapults MPX into totally uncharted territory. Mounted on a side-folding strut, PSB brings carbine-grade controllability and accuracy to a platform that still transfers like a conventional handgun.


Thanks to Operation Nimrod in 1980, wherein the British SAS, armed with MP5 submachine guns, took down an embassy full of terrorists on live international television, everybody with a badge suddenly had to have a set of black fatigues hanging in his closet and an MP5 in the trunk of his squad car.

About a zillion MP5s later, somebody decried the 9mm as inadequately powerful, and the entire Free World divested itself of their submachine guns in favor of rifle-caliber carbines. Some might think the humble submachine gun would at this point die a natural and dignified death.

Carbines chambered for 5.56mm can now indeed be had in briefcase-sized packages, but the resulting noise is indescribable and the muzzle flash in dim light is adequate to burn your retinas. Touch one of these things off for real in an enclosed space and you won’t be doing any communicating for a while.

Combine this with quantum advances in bullet design that make the humble 9mm markedly more effective than was once the case, and you have a recipe for a subgun resurgence.

Right side of the SIG MPX
Bolt release and magazine catch and safety (not shown) are as readily accessed on the right side of the SIG MPX as the left.



Nobody does it like SIG Sauer. They study American firearms law and meticulously craft guns to fit within it. Nothing exemplifies this adage better than the MPX. The SIG MPX is what would happen if you purpose-designed an M4-style firearm around the 9mm cartridge and added all the bells and whistles.

The MPX is a gas-operated, piston-driven design not altogether unlike your grandfather’s M1 Carbine. The bolt release, safety, and magazine catch are perfectly mirrored on both sides of the weapon, and a flip-open polymer dust cover is over the ejection port.

Barrels are readily replaceable, and caliber changes in .40 S&W as well as .357 SIG are currently pending.

Blackhawk’s line of MP5 pouches is functional and effective
When Short-Barreled Rifle paperwork comes back approved, just drop a sliding stock on to tail end of Zenith Z-5 and you’re ready to rumble. Blackhawk’s line of MP5 pouches is functional and effective.


The KeyMod forearm accepts all manner of tactical bling, and the full-length top rail will mount up any proper combat glass. The translucent polymer magazines incorporate steel feed lips and are just a wee bit too big to fit in standard MP5 pouches. The addition of one of those delightful SIG Pistol Stabilizing Braces on a folding strut lets you own a short-barreled semiautomatic submachine gun without any extraneous NFA (National Fire-arms Act) registration baggage.

BATF has been fairly schizophrenic regarding the legality of firing a pistol equipped with a Pistol Stabilizing Brace from the shoulder. At the present time using a PSB from the shoulder makes the MPX a short-barreled rifle and illegal unless the proper paper work has been completed and registered with BATF.

While the MPX is legitimately revolutionary, the gun everybody’s comparing it to is the HK MP5.

Accessory rails on KeyMod forearm of MPX
Accessory rails on KeyMod forearm of MPX allow attachment of any standard lights or lasers. SureFire X400 incorporates brilliantly bright white light and easy-to-acquire green laser designator.



The Zenith MP5 is called the Z-5 and is manufactured on licensed HK machinery in Turkey by the MKE company, a weapons production firm with more than 500 years’ experience producing ordnance. Their guns are faithful renditions of the German originals in 9mm, .223, and .308.

Their 9mm offerings can be had with standard 8.9-inch barrels, long 16-inch tubes, or stubby MP5K configurations replete with factory accurate receiver reinforcing plates.

The Zenith Z-5 is the most faithful rendition of the MP5 ever of-fered on the American market, as the fire control group mounts with a pair of pushpins just like the originals. There is also a steel lip that precludes unmodified full-auto trigger packs, and a steel block that excludes factory full-auto bolt carriers to satisfy import restrictions … but none of that shows from the outside.

SIG Sauer STS-081 sighting device
SIG Sauer makes its own line of electronic sighting devices.

Where once HK accessories such as lights, stocks, and magazines were prohibitively expensive, nowadays such items are pleasantly plentiful and available at decent prices. I landed both a sliding stock and the surplus SureFire lighted forend for less than $100 each after some patient Googling.

I did the paperwork to register my Zenith Z-5 as a short-barreled rifle and dropped in the sliding stock without a fuss. The registration costs $200 and is indeed administratively onerous, but by the time you read these words, the Chief Law Enforcement Officer signoff will no longer be required, so the process is not as painful as it once was. The BATF Form 1 required to undertake this adventure is available, along with instructions for its submission, on the ATF website.

SIG MPX charging handle functions identically to that of an M4 but comes standard with bilateral latches.
SIG MPX charging handle functions identically to that of an M4 but comes standard with bilateral latches.


Both guns are comparably smooth on the range. The operating systems are entirely dissimilar, but the recoil impulse for each is negligible. Neither trigger lends itself to pinpoint accuracy at long ranges, but if your targets are lurking out at half a kilometer, you need a different tool. Double taps are dreamy through both weapons, and either gun runs circles around a comparable rifle-caliber platform indoors.

Additionally, my Gemtech GM9 suppressor is comparably effective on either platform, though the MPX muzzle is threaded to a left-hand European standard and requires an adapter and a bit of thread locker to accommodate the can.

Magazine changes on the MPX are the same as those on a top-end ambidextrous M4, only faster. Mags drop free easily, and the translucent nature lets you keep track of rounds remaining at a glance. When the gun is empty, stroke the magazine catch, slam in another magazine, hit the bolt release, and go.

Magazine changes on the MP5 are slower but cooler. Lock the bolt to the rear, replace the magazine with a fresh box, and slap the charging handle down to drop the bolt, like Bruce Willis in Die Hard. The process is incrementally more cumbersome than that of the MPX, but not by much. Like most things, it just takes a bit of practice.

SIG MPX offers carbine performance in a handgun package
SIG MPX offers carbine performance in a handgun package. Sporting familiar M4 controls and superb ergonomics, this nifty new gun from SIG breaks new ground in the American tactical firearms market

MP5 magazines are steel with chromed followers and are widely available at reasonable prices. MPX mags are more expensive and in current production.


Both guns were comparably accurate and reliable with both ball ammo and high-tech hollow points. The MPX comes with a nice set of flip-up iron sights, while the MP5 runs off the standard fixed post front and rotating diopter rear sight common to all HK long guns. Adjustment of the HK rear sight requires an inexpensive tool. The Zenith MP5 comes standard with a removable optics rail that is rigid and easy to use.

Given their long magazines, neither gun runs well from the prone, but weight is about the same for each, and both ride very comfortably on a sling. The MPX comes with a single-point bungee and the MP5 with the standard ludicrously complicated, but undeniably versatile and effective, HK sling system.

I could reliably ring steel a football field away with both guns using their iron sights and could manage headshots at the same distance with some decent optics. For operators inured to the muzzle blast, recoil, and flash of short-barreled rifle-caliber guns, these two 9mm rigs are refreshing, effective, and fun.

Gemtech GM-9 G-Core sound suppressor
Gemtech GM-9 G-Core sound suppressor runs comparably well on Zenith Z-5 as it does on SIG MPX, though MPX requires an adapter to fit device to its left-hand European threads.


The two guns cost about the same. The Z-5 requires a transfer tax to install a stock legally, but in return you remove all the legal ambiguity out of running the gun from the shoulder. It’s hard to believe, but MP5 magazines and accessories are cheaper, though the MPX gear is indeed state of the art in materials and engineering.

Pick your poison. The MPX is the new kid, transfers as a simple handgun, and oozes sex appeal as a result. But the Z-5 has the street cred and is an indisputably successful real-world combat veteran. I couldn’t decide, so I resolved to eat Ramen noodles for a couple months and kept them both.

SIG MPX and Zenith Z-5
SIG MPX and Zenith Z-5 are two very different so-lutions to the same problem. Both performed very well.

For any proper gun nerd, the MPX and the Z-5 are both pure re-fined awesomonium.

Will Dabbs grew up in the Mississippi Delta and has a degree in Mechanical Engineering from the University of Mississippi. He is Airborne qualified and accumulated 1,100 hours flying UH-1H, OH-58A/C, CH-47D, and AH-1S helicopters. He currently works in his own medical clinic and maintains a licensed 07/02 firearms manufacturing business building sound suppressors. He has written on the subjects of firearms, medicine, and survival for more than 20 years.


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