HK’s SP5K: The New Semi-Auto German Room Broom

Will Dabbs, MD, Photos by Cassie Dabbs

The new HK SP5K is a simply ludicrous firearm. It weighs two and one half times what a Glock 17 does and is as big as a hubcap. The trigger is long and thick like that of the submachine gun that birthed it, and you can’t hide it underneath anything less imposing than a pup tent or a burqa. The SP5K also costs a holy fortune. There are literally dozens of cheaper, lighter, more convenient ways to throw 9mm rounds downrange; however, I simply must have one. As gauged by the backlog that HK currently has in delivering the SP5K, apparently every other gun nerd in America wants one as well. For all the admittedly derogatory stuff listed above, the new HK SP5K remains just incredibly cool.

First Impressions

Let’s start with the box it came in. Holy crap. If the gun in this box fell out of the International Space Station it would, after an uneventful atmospheric re-entry, bounce harmlessly off the surface of the earth and leave the weapon otherwise unscathed. If James Bond could not disarm the thermonuclear warhead that threatens to obliterate the planet he needs only get the ticking nuke inside this box and seal it up prior to detonation to render the weapon otherwise harmless. Like everything about the SP5K, the gun’s shipping case is monumentally over-executed. This massive lockable polymer carrying case seems nigh indestructible and is fully sealed against any environmental contaminants should you need to operate the SP5K in outer space or on the ocean floor. I haven’t yet figured out what else you might use the case for, but rest assured, it would be something “HK epic.”

The gun itself is perfectly executed. Everything about the weapon is sharp, crisp and professional. HK has elevated the mass production of stamped steel firearms to an art form. The baked-on black enamel finish is gorgeous, the welds are flawless, and the fit is glassy smooth throughout. The takedown pins are sturdy enough to keep the gun together under hard use yet push out effortlessly using nothing more complicated than a human finger.


In the early 1950s the German firm of Heckler and Koch operated a factory in Oberndorf, Germany, producing, among other things, sewing machine parts, machine tools and bicycles. HK was scraped together in the aftermath of the massed Allied bombing campaigns of World War II using talent and equipment salvaged from the rubble of the Waffenfabrik Mauser factory. In 1956 HK submitted a proposal to the West German government to arm the Bundeswehr. In 1959 the G3 was thusly selected, and HK formally became a weapons manufacturer.

Spanish heritage notwithstanding, the action of the G3 ultimately descended from that of the MG42 belt-fed machine gun. The MG42 operates via a delayed roller-locked design wherein roller bearings are cammed into recesses milled into the chamber end of the barrel assembly. These roller bearings provide sufficient resistance to keep the bolt closed until pressures drop sufficiently to warrant safe extraction. The benefits to this system include relatively simple construction and, in the case of the MG42, a blistering rate of fire. Such weapons are also exceptionally reliable in the face of battlefield detritus.

Late in the war Mauser engineers combined the MP44 and MG42 into the MKb Gerat 06 that subsequently evolved into the StG45(M). A mere 30 rifles were completed by war’s end. This next generation replacement for the MP44 fired the same 7.92x33mm intermediate cartridge but operated on the roller-locked principle of the MG42. German engineers took samples of the StG45(M) to Spain after the war and subsequently designed the Spanish CETME. This stamped steel assault rifle morphed into the HK G3 that was sold to the West German Bundeswehr. The G3 subsequently served with distinction around the world. Untold hundreds of thousands of these rifles were employed and consumed in African bush wars and throughout the Middle East. The G3 was also license produced in Pakistan, Denmark, Turkey, Iran and Luxembourg.

Shrinking the G3 Down to Size

The MP5 is the fourth generational iteration of the G3. After the G3 was perfected, HK engineers rechambered the gun to fire the Combloc M43 7.62x39mm round followed soon thereafter by a 5.56x45mm version. Then in 1964 they redesigned the G3 to fire the 9mm Parabellum round and designated the new gun the HK54. Two years later the German Federal Police adopted the weapon as the HK MP5.

The MP5 is just crazy complicated. While open bolt submachine guns such as the Uzi and Swedish K are the chemical formula for simplicity, the locked breech MP5 is an order of magnitude more complex. The MP5 incorporates the same locking system of the G3 along with its complicated selective fire trigger pack and fluted chamber. Where the Uzi might seem like a tire iron, the MP5 is a sewing machine.

In 1976 HK came out with the MP5K. The K model dispensed with a shoulder stock in favor of a butt cap with a sling mounting swivel, a slightly shortened receiver and a barrel chopped from 8.9 to 4.5 inches. The standard forearm was replaced by a vertical broomstick grip while the sights and fire control group remained the same. The MP5K was specifically designed for undercover employment by executive protection details and similar covert applications.

As an aside, the term “butt cap” is a multifunction idiom. Sling it as an epithet as in, “You, sir, are a butt cap,” and your target doesn’t know if he has been insulted or not. Not unlike the moniker “Wankel Rotary Engine,” nothing about the words is innately objectionable, it just seems as though they should be.

The 1980s—Big Hair, Loud Music, Cool Guns

In the 1980s the sleeping giant that is the American civilian firearms market was just beginning to stir. Back in those heady days an American gun nerd could choose from genuine semi-auto versions of the Steyr AUG, the Israeli Galil, the Uzi and all three of the standard HK centerfire combat guns. The HK 91, 93 and 94 were chambered for .308, .223 and 9mm, respectively. For the most part if you wanted an AR-15 you could buy a Colt or just go without. The HK94 was a long-barreled semi-auto variant of the MP5. Introduced in 1983, this gun carried an MSRP of $650 with a fixed stock. The sliding stocked version ran $720. That’s about $1575 and $1745 respectively in today’s dollars. 15,633 copies of this weapon were imported.

Six years later HK began importing the SP89. SP stood for Sport Pistole, and the SP89 was a semi-auto rendition of the stubby MP5K. In the case of the SP89, the broomstick foregrip was replaced with a simple polymer forearm to comply with inane American restrictions on vertical foregrips on handguns. The SP89 transferred like any other pistol.

Alas, most all of these cool black guns fell prey to import bans enacted via executive order by both President Bush the First and subsequently Bill Clinton. As a result, while domestic production of such guns was unaffected, all imports were summarily halted. Original preban versions of these weapons immediately skyrocketed in price. These same guns command a premium to-day on the rare occasion they can be found for sale.

The Information Age Treatment

Now fast forward some 30 years and much has changed. There are now between 15 and 20 million black guns in circulation in America, roughly one for every 16 Americans of all ages. The delusional hallucinations of leftist politicians notwithstanding, black guns are now firmly ensconced within mainstream America. Nowadays AR-15 accessories and caliber options are appropriate water cooler topics across our great republic. Into this fertile soil HK is now sowing a new semi-auto version of the MP5K submachine gun.

The SP5K ships with two 30-round magazines for those living in the free states. The magazine release is a button on the right side of the magazine well. The polymer forearm is nearly identical to that of the original SP89, and it extends out ahead of the muzzle just far enough to keep fingers clear. Today’s version also includes a Picatinny top rail for accessories. While this rail is technically removable, it is secured with Torx screws for reliable stability. The butt cap (there’s that phrase again) sports a sling swivel, and the gun comes with a cool single-point bungee sling. The rear portion of the receiver includes small stiffening plates welded to both sides just like the MIL-SPEC MP5K.

The gun runs exactly like an MP5. To load the weapon you lock the front-mounted cocking handle to the rear and insert a loaded magazine. Slap the cocking knob down to drop the bolt. The two-position pictogram lower is self-explanatory. There is no last round bolt hold open. When the gun runs dry you lock the bolt to the rear and change magazines.

Practical Tactical

Running the SP5K demands a unique manual of arms. The gun hangs underneath the strong side armpit and pivots instantly into action. To fire the SP5K one extends the gun against tension on the sling system and sights above the weapon. The precision diopter sight is nothing more than ballast when employed in this manner. However, the Picatinny rail does allow the incorporation of any typical electronic sight. I mounted up my trusty EOTech Holosight and went to town.

In action the SP5K runs fast and points naturally. The weight of the weapon combined with its superb closed-bolt, locked-breech action makes it an accurate platform at appropriate ranges. The 30-round magazine lasts about forever. Magazine changes are slower than they might be on your Glock 17, but you earn extra style points when you slap the charging handle down to close the bolt. Shooting from a rest at 15 meters, the gun left several big ragged holes.

The Real Skinny

The MSRP for the SP5K with a brace of magazines is $2699. That is utterly insane for a 9mm pistol that weighs several multiples of what your typical plastic handgun might and then yet won’t run quite so quickly. The magazine release is hard to reach, and the safety is stiff. However, the gun is already backordered. A Glock 17 with an extended magazine will do most everything the SP5K will do at one-fifth the price. If that is the case, why shell out a substantial bundle of your hard-earned cash to make one your own?

I could wax poetic about the MP5 being the weapon of choice for some of the world’s premiere counterterrorist units and HK’s decades-long reputation for quality and superlative design. I could extol the gun’s many salient virtues and try unsuccessfully to deflect skepticism with the lame observation that HK accessories are cheaper now than they once were. Where previously they were obscenely expensive, now they are just preposterously so. However, at the end of the day none of that matters.

The SP5K is selling as fast as the guys at Oberndorf can push them out the door simply because it is so freaking cool. It has been said that anyone who might speak disparagingly of owning a quarter million dollar sports car has likely never driven a quarter million dollar sports car. That sagacious axiom applies to this particular circumstance as well.

I can think of scads of cheaper, lighter ways to throw 9mm Parabellum rounds downrange. However, the HK SP5K does it with so much more style. Don’t hate—embrace the horror, and think back to the first time you saw Bruce Willis wield an MP5 in Die Hard. Now lie to your spouse, sell your car, take a second job or hock a kidney (why else might God have equipped you with a spare?). Welcome to the Dark Side—an eerie place populated by gun nerds who buy weapons for less than practical reasons. It’s more crowded down here than you might think.

Technical Specifications: HK SP5K
Caliber: 9mm
Operating Principle: Roller-Delayed Blowback
Mode of Fire: Semi-automatic
Magazine Capacity: 10, 15 and 30 rounds
Length: 13.9 inches
Width: 2.4 inches
Height: 8.66 inches
Barrel Length: 4.53 inches
Sight Radius: 10.2 inches
Weight (Empty): 4.64 pounds
Trigger Pull: 6.7-10.1 pounds
Trigger Travel: 0.24 inches
Trigger Return: 0.12 inches
Barrel Profile: 6 grooves, right-hand twist
MSRP: $2699

This article first appeared in Small Arms Review V21N9 (November 2017)
and was posted online on September 22, 2017


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