The Z-008 III of the Zbroyar company in Kiev, Ukraine, can best be described as a bolt-action rifle with AR-looks. We have seen that before. But the Z-008 is not just a fashionably dressed repeating rifle. The weapon has been specially designed in this configuration and is full of gadgets.

The Ukrainian firm Zbroyar (which translates as “weapon maker”) is a private company established in 2004. The company in Kiev focuses on guns for sports, hunting and military use. Production, assembly, finishing and surface treatment are largely done in-house, using modern CNC machines and with a quality comparable to or better than many Western European companies.

At present, Zbroyar produces three types of weapons: the Z-15 (based on the AR-15) in 5.56x45mm (.223) NATO or .300 Blackout caliber, the Z-10 (based on the AR-10) in 7.62x51mm (.308) NATO caliber and the Z-008 III. The Z-008 III is the subject of this article.

The Z-008 is not restricted to any specific caliber. The construction of the gun, with a separate barrel extension, makes it relatively easy to change the barrel (and therefore caliber), which makes it a good choice for long-range shooters.

Description

The Z-008 is a bolt-action rifle. The Roman numeral III stands for the third generation of the gun, as Zbroyar previously made several conventional Z-008 bolt-action rifles. The weapon is completely built in Kiev. Only the AR-stock and pistol grip are aftermarket parts, made by Magpul on the rifle pictured here. The magazine of the illustrated gun is also by Magpul, but of course there is a wide choice in this area.
The Z-008 is a fascinating combination of bolt-action rifle gun and AR. The weapon has the ergonomics of the latter, in terms of the position of the double-sided safety and single-sided magazine catches. The aluminum handguard with its mounting rails and the design of the construction with an upper and lower frame have also been copied from the AR. But since this is a bolt-action rifle, there is no gas block, cocking handle or forward bolt assist. The right side of the solid aluminum ‘upper’ has two elongated openings. The front one is the ejection opening (without a hinging lid), and the rear is for the bolt handle.

The height of the upper part of the receiver is almost the same as that of a semi-automatic rifle, which means it is almost seamlessly continuous with the handguard. To give the upper sufficient rigidity, the top part contains a steel cylinder, of which only the back is visible when the weapon is disassembled.

Unlike a semi-automatic, the Z-008 trigger mechanism is an integral part of the upper frame. The Z-008 comes standard with a single stage trigger mechanism designed at Zbroyar, but the construction is such that it can be exchanged for one of the main brands for an aftermarket trigger.

Extras

The Z-008 bolt has a narrowed bolt head with three locking lugs. The front of the bolt has the extractor, which has been mounted from the rear. It is a Zbroyar design, comparable to a Sako style extractor. The ejector is a spring-loaded plunger in the bolt head.

To maintain the best possible fit between the bolt and frame, Zbroyar added two extras. First, the body of the bolt has been extended to the rear, by means of a detachable end cap. A longer bolt automatically means less play. But as the bolt now travels further to the rear, the buffer and buffer spring had to be removed from the stock, which now has an empty tube with room for the rear part of the bolt. A second characteristic is a steel U-profile, put in the left lower side of the upper receiver. The axis of the bolt handle protrudes from the opposite side of the bolt. This notch runs in the U-profile and secures a tight guide. The U-profile bends upward at the point where the bolt handle is turned downward. This prevents wear to the aluminum upper and aids in primary extraction when the bolt is opened.

Operation

As far as operation is concerned, the Z-008 is simplicity itself. Insert the magazine, operate the bolt and the gun is ready to fire. The magazine housing is asymmetrical. The right wall is shorter than the left, making it easier to insert a magazine in a prone position. The magazine is a standard AR-10.

The firing pin is cocked when opening the bolt. A tooth on the bottom of the firing pin locks in the rear of the bolt body. If the bolt is completely closed, this tooth is released but is then caught by the trigger sear. This is similar to 99% of all other bolt-action rifles, comparable to the reliable operation of the mother of all modern bolt-action rifles, the K98. A small notch with a red ring protrudes from the right side of the upper receiver, giving visual and perceptible evidence that the bolt is cocked. The gun has an ambidextrous safety catch, but only the left side of the receiver is marked with “FIRE” and “SAFE.”

Disassembly

Like the AR, the upper and lower receiver are connected with two cross-pins. When the rear pin is pushed out to the right (it won’t fall out), the lower receiver pivots open. For normal maintenance, that is enough. A special pin now blocks the mechanism to ensure that the weapon cannot be fired.

With the stock out of the way, the bolt can simply be pulled out to the rear of the receiver. To dismantle the bolt, one must first remove the end cap, which is fastened with a bayonet catch. If the cap is turned clockwise, it can be pulled from the bolt body. Next, the firing pin case and firing pin can be pulled rearward out of the bolt. The bolt head is attached to the bolt with a solid crossbolt, in turn fixed by a pin. If this little pin is removed, the crossbolt can be taken out and the bolt head separated from the bolt. The front part of the bolt has a smaller diameter than the rear and the bolt head. It is fitted with a synthetic sleeve, which reduces friction when operating the bolt.

Shooting

We fired the Z-008 III, equipped with a Tier-One Spartan III silencer and a Kahles K 624i 6-24×56 scope, at a 100-meter range, with Lithuanian GGG Ammunition. That distance is almost an insult for the rifle, with a group of roughly half an inch. The bolt runs very smooth, cartridges fed without any problems, and the trigger is excellent. The European importer, the Dutch company PIROSPORT, also specializes in custom-made barrels. It prepared a first run in 6.5x47mm Lapua, but the Zbroyar ZB-008 III can be made in any caliber of the .308 (short action) family, like .243 Win., 6mm BR, 6.5 Creedmoor, .260 and the 7mm-08. The gun is being used as a military sniper rifle as well.

In the 1990s, the arms collector’s world was excited by the discovery of a Luger self-loading rifle with a toggle-lock, developed shortly before World War I. Here is something more unique: a prototype Borchardt toggle-lock rifle from that same period.

For most of their lives, weapon designers Hugo Borchardt (1844–1924) and George Luger (1849–1923) were fierce competitors. It is, of course, well known that both were involved in the early stages of development of a self-loading pistol, with Luger modifying Borchardt’s original design into the famed Parabellum pistol. It is far less well known that both Luger and Borchardt occupied themselves with the design of a semi-automatic rifle shortly before the outbreak of World War I.

Until the 1990s, there were mostly rumors and scraps of information, but then there was a spectacular find: a semi-automatic Luger rifle with a toggle-lock, serial number 4, in the German military caliber 7.92×57. The weapon reportedly emerged in Britain in the amnesty of 1988 and finally ended in the collection of arms dealer Samuel Cummings. For a long time, it was debated whether this was an original gun or a very clever forgery, but eventually the weapon turned out to be genuine and a number of associated patents were found.

Lawsuit

The veil was lifted further when a part of Georg Luger’s estate was bought by a European collector. Among the personal papers were documents concerning a lawsuit in 1920 between Luger and his former employer, Deutsche Waffen- und Munitionsfabriken (DWM). Luger could never quite get along with the general manager of DWM, Paul von Gontard. Disagreements eventually ran so high that Luger was fired. That, in itself, did not bother him. He objected, however, to the fact that DWM claimed the rights to the semi-automatic rifle he had developed.

One of the documents that Georg Luger presented to the court was a letter from the Prussian War Department in Berlin to DWM, dated March 2, 1914, in which the ministry expressed its interest in further tests with the Luger rifle. The same letter gave a less favorable opinion on another gun offered by DWM for trials: a Borchardt semi-automatic rifle.

Deficiencies

The Prussian authorities considered the 4.8-kilogram Borchardt rifle too heavy and difficult to disassemble. In addition, it was found to have several mechanical defects. The weapon had a toggle-lock combined with a fixed barrel. The result was that the breechblock would already begin its rearward movement when the bullet was still in the barrel, so that part of the cartridge case had to withstand the full gas pressure. The toggle joint that slammed to the rear was considered potentially dangerous to the shooter, especially when kneeling or in the prone position (which, by the way, was equally true for Luger’s gun).

The toggle-lock of the Borchardt rifle operated under the pressure of a heavy coil spring, which was located longitudinally behind the magazine. The force of the spring was transferred to the toggle-lock through a chain, as shown in Borchardt’s German patent 241,941 and U.S. patent 1,160,831. The Prussian War Ministry did not like this construction. Installation and removal of the chain was too complicated for the ordinary soldier, and the links collected dirt and dust. Finally, the self-loading mechanism did not work with blank cartridges.

Where, Oh Where?

The letter from the War Ministry provides indisputable evidence that the Deutsche Waffen- und Munitionsfabriken had offered both a Borchardt and a Luger self-loading rifle to the Prussian authorities for trials, prior to World War I. The Luger gun had already surfaced. But where was the Borchardt rifle? Quests for this unique piece at first only yielded a series of patents, issued from May 1908 onward:

DRP 213,012 from May 17, 1908;
DRP 241,941 from March 1, 1911;
DRP 262,217 from February 11, 1912;
DRP 262,217 from April 17, 1912;
DRP 279,184 from February 22, 1914.

The rifle is best illustrated in German patent 241,941, and in U.S. Patent 1,160,831 for which the application was filed on February 2, 1914. Both are reproduced here, showing small differences in the artwork.

However, all this did not answer the most important questions: Had the Borchardt self-loading rifle survived? And, if so, where? As can be seen from the pictures, we can answer that question: A prototype does exist, and it is in the collection of the Museum of Artillery, Engineers and Signal Corps in St. Petersburg, Russia.

Description

The weapon in the museum is similar in almost all respects to the drawings of the German and U.S. patents. The gun is unnumbered, in the white (like many prototypes) and has no visible markings. It lacks both Borchardt’s name and the DWM logo, and it has no proof marks. Apart from some minor damage, the metal is in good condition, but the stock has suffered considerably. As can be seen in the pictures, the wood is full of dents and scratches. The only missing part is the leaf spring that secures the barrel band.

At first sight, the Borchardt rifle looks like the front of a Gewehr 98 has been combined with the rear of a Garand, with the toggle of the Parabellum pistol. The Borchardt rifle has a detachable magazine with a five-round capacity for the German standard 7.9×57 military cartridge. The magazine catch at the front of the magazine housing is U-shaped with two arms on either side of the magazine. The magazine is held in place by two studs on these arms, which fall in the small rectangular openings at the sides of the magazine. Pressing the catch to the rear forces the studs outwards and releases the magazine.

Knee Joint

The most spectacular part of the Borchardt rifle is, of course, the beautifully made toggle-lock, which resembles that of a Parabellum pistol on steroids. It must have been a difficult job to figure out the kinetics. The breechblock must move to the rear sufficiently, to be able to pick up and chamber a full-size 7.9×57 round, which means the toggle joint must open accordingly. The layout of the lock remained unchanged: first the breech block with a combined loaded chamber indicator and extractor in the top, and then the two joints of the toggle.

In order to prevent the breechblock from rebounding due to the blow against the back of the barrel, the left side of the receiver has a spring-loaded metal plate which falls into a recess in the left cocking knob. The left side of the receiver also has a sliding safety catch and a sear bar just like the Parabellum pistol.

So, you may ask, why are there no pictures of the internals of the gun? Well, there simply was no time to take them. The Museum of Artillery, Engineers and Signal Corps has a collection of about 60,000 firearms, which might well make it the largest museum collection in the world. When our small group was at the museum, we had just a few days. So, there was a choice: go into a few dozen guns in depth or photograph as many as possible. We chose the latter. So even if it’s a glimpse, it’s a glimpse of one of the rarest guns in the world: the Borchardt semi-automatic rifle.

Unknown

The intriguing thing about this statement, of course, is that thus far these weapons have never been shown. Even the former German quarterly Waffen Revue has never mentioned them, though it was known for its thorough documentation about German war developments. Alas, one would say, one more piece of history lost.

Fortunately, things turned out differently because there is such an institute as the Army Museum in Prague – a museum with a fantastic collection, and an old-fashioned way of preserving it. It got me thinking; a museum in Prague and a war-time development in Brno? Could it be that one of these grenade rifles had been saved?

On a visit to the museum with my friend Leszek Erenfeicht, I took the list of projects of the Sonderkommission with me. Our host, curator Jan Skramoussky, thought for a moment, said, “I’ll have a look” and then disappeared into the catacombs. After fifteen minutes he came stumbling back. Not with one, but with four grenade rifles. And all four were different!

Unique

These weapons are truly unique. Since my visit to Prague, I have tried to find further information, but without any success. Regrettably, we must do only with a detailed description.

First the big picture. There are four shoulder firearms with a rifled barrel for firing rifle grenades, and with a special mechanism to absorb the recoil forces. All four are marked with a trademark and/or model designation and serial number:

1. Factory marking Z in circles, model designation ZK 424, serial number SK 0051.
2. Factory marking WAFFENWERKE BRÜNN A.G., no model designation, serial number No. 10.
3. Factory marking WAFFENWERKE BRÜNN A.G., model designation GBSS43, serial No. 07.
4. Factory marking WAFFENWERKE BRÜNN A.G., model designation GBSS43, serial No. 11-IV.

Weapon numbers 1 and 3 have a rotating barrel with a bayonet closure. Weapons 2 and 4 have a tilting barrel. The barrels are chambered for a special 7.9mm cartridge for firing rifle grenades. Their front section is rifled.

The letters ZK stand for a design of the Koucký brothers, while GBSS43 stands for Gewehrgranaten-Büchse SS 43. This is a rather enigmatic designation. Would the weapons have already been developed in 1943? And if so, how is it that in April 1944 only four pieces were available for testing? Unfortunately, we do not have an answer.

Another question concerns the chronological order of these four guns. The most logical seems the one in which they are listed here. ZK 424 is a factory designation, which was used for weapons that were still under development. There is a good analogy: the ZK 403 submachine gun, also by Koucký. Only when the SS planned to adopt it was renamed Maschinenpistole 42. Therefore, it seems plausible that the ZK 424 preceded the other three models. Weapon number two seems a logical next step, with only the brand name used by the Germans and no model designation. And then there are the two specimens with the manufacturer’s name and model designation, one with a number 7 and one with number 11. We can only guess at the meaning of the Roman numeral IV added to the last gun’s serial number. The fourth version of serial number 11? That does not make sense.

In the following, the four arms will be discussed separately. Unfortunately, many questions remain unanswered. But in any case, the existence of these weapons is now known.

ZK 424

Its outer appearance is simple: a tubular housing of sheet steel with a wooden butt-plate and two pistol grips, identical to that of the vz. 26 light machine gun and its successors (the front grip being reversed). Internally it is a different story. The mechanism of ZK 424 consists of three complex, solid steel main parts: the barrel with its locking lugs, the breech head with the firing pin, extractor and ejector, and the breech block. At rest, all three are interconnected. The barrel has two locking lugs at the rear, which fall into corresponding recesses in the breech head – the reverse of a bolt action rifle. The bolt head has a rear recess that falls like a bridge over the narrowed front section of the breech block.

To load the weapon, the barrel must be opened. The ZK 424 barrel has eight lands and grooves. On the right is a handle, slid with two rails in recesses of the barrel block, and fastened with a thick screw.

The base of the handle has a spring-loaded cam, which rest in a recess of the breech block, just ahead of the extractor, when the weapon is closed. If the spring-loaded lever of the handle is pressed, the cam is pulled inward. The barrel can be rotated upwards, which causes the lugs to rotate out of their recesses in the breech head. If the barrel is free, it can be moved forward so that a cartridge can be loaded in the chamber. When unlocking the barrel, a sloping cam pushes the firing rod backwards, so that the firing pin is cocked.

When the barrel is closed, it moves the cartridge in front of the firing pin. The firing pin is cocked. The only thing left is to load a rifle grenade in the muzzle end.

The ZK 424 has no safety, but a peculiar trigger mechanism. This consists of two vz. 26 pistol grips with part of the original trigger mechanism. The rear one is still clearly recognizable. The front one has the pistol grip and trigger removed (the hole for the shaft of the pistol grip is still visible). A plate extends from the rear to the front unit. When the trigger is pulled, that plate is pulled backwards. The sear in the front unit pivots, thus permitting the firing pin to strike forward.

After the shot the whole mechanism moves backwards in the receiver to soften the recoil. The huge recoil spring captures the moving parts. At the end of its movement this spring pushes the complete mechanism forward again. If the barrel is opened again, the empty case of the cartridge is withheld by the extractor and when the barrel moves forward, it is pushed sideways by the ejector in the breech head. The ZK 424 has no sights or sight base and no lanyard rings.

Weapon Number 10

The second grenade rifle, with the factory marking Waffenwerke Brünn, but without model designation, is very different. It is a somewhat futuristic looking weapon, with a relatively simple construction. This version has a tilting barrel, similar to that of an air rifle. The mechanism consists of the rifled barrel, hinged between two wings of the receiver. Behind the barrel is a locking latch, which also serves as the upper part of the cartridge chamber. The latch looks like an inverted U. Its legs have notches, which fall into recesses in the receiver and thus hold the barrel closed.

As the knurled knob of the latch is pressed, these notches slide out of their recesses and the barrel can be opened. If the barrel is fully opened, two springs push the latch to the rear, which in turn extracts the empty cartridge case. The barrel does not hinge that far open, and space is limited. The top of the housing has a recess to facilitate the loading of a new cartridge.

The firing mechanism of the weapon is completely hidden in the housing, impossible to dismantle without proper tools. Therefore, we can not show any details.

At the left side of the pistol grip is a safety lever, with two positions labeled F (Feuer) and S (Sicher). After the shot, barrel and receiver move backwards inside the housing. On the left side of the frame is a T-shaped pedestal for a grenade sight, with increments up to 331 (!) meters.

Mechanically, this grenade rifle is of brilliant simplicity. Field stripping is a matter of seconds. Barrel and receiver can be pulled forward out of the housing after pressing the latch on the front pistol grip. The sheet metal butt is fixed to the housi

The other two rifles are both marked on the top of the receiver with the name of the factory, Waffen Werke Brünn AG, and the model designation GB SS 43. And there we have pretty much the only thing they have in common, because both function completely differently. Even the model designation is spelled differently. One model shows the SS runes between dashes, the other not.

GB No. 7

This weapon has the lowest serial number; Gewehrgranaten-Büchse No. 7. The weapon has a lot in common in terms of construction with the ZK 424. On the barrel there is a handle, with which it can be turned, and then can be slid open forwards. A cartridge can be placed in the chamber. If the barrel is closed, the handle acts as a front pistol grip.

With its typical flare-shaped mouth, the weapon looks like a combination between a rocket launcher and a pirate gun. Although it looks fairly simple on the outside, the interior is just as complicated as the ZK 424. Weapon No. 7 has a sheet steel receiver, consisting of two parts. The rear part has the butt, main spring, breech block and the firing mechanism. The front part contains the barrel and the front pistol grip. This piece acts in fact as a barrel shroud. To load the rifle, the catch behind the front pistol grip must be pressed. The barrel jacket and barrel can be turned 90 degrees clockwise and pushed forward. Subsequently, an ignition cartridge can be loaded in the chamber.

The barrel of No. 7 has two lugs at the rear, just like the ZK 424. These lugs rest in recesses in the front of the breech block. Again, the firing pin spring is cocked when the barrel is rotated to open. However, unlike the ZK 424, the breech block does not consist of two parts, but of only one, albeit in the form of a very complex milled piece.

Number 7 again has a huge main spring, which is enclosed between two caps. The front cap lies around the breech block, the rear around a perfectly fitting wooden plug, which in turn rests against the inside of the butt-plate. When the shot is fired, barrel and breechblock recoil together and here again a ‘limiter’ inside the breech block captures them in their forward movement.

Grenade Rifle number 7 has a huge trigger guard, so that the weapon can also be operated while wearing gloves. The safety is on the left of the trigger housing, with the markings F (Feuer) and S (Sicher). Above the trigger is a bracket for the grenade sight. This is virtually identical in construction to that of weapon No. 10, but has a different graduation. This sight runs up to 200 meters. At the right of the butt plate and on the barrel shroud are two sling swivels to carry the weapon across the shoulder. On the left side of the receiver is a leather cheek piece, but this has only very limited use. The front and rear sights are positioned so far to the left that the head of the shooter, while aiming, does not even come near the cheek piece. Apart from that, the grenade sight is not practical either: at most distances, the hand that grasps the front pistol grip blocks the view between front sight and target.

The sheet steel receiver/housing of this Grenade Rifle is a masterpiece of industrial design and engineering, very suitable for mass production. This contrasts sharply with the extremely complex shape of the barrel and breech block. The usefulness of the flared-shaped mouth is unclear.

GB No. 11

We do not know what is meant by the Roman numeral “IV” after the serial number on Gewehrgranaten-Büchse number 11 – IV. The fourth version? In any case, it is a weapon with a tilting barrel again. The construction of the barrel and the receiver resemble that of the weapon with number 10, with an almost identical locking pawl annex ejector. However, number 11 has a very different mechanism to absorb recoil. It is the only weapon we have ever seen with a friction brake.

The housing of Gewehrgranatenbüchse number 11 has a cross-shaped cross section. In the left and right arm of the cross there are two rectangular guide rods. The receiver has double wings at the left and right. The wings fit exactly in the lateral arms of the housing, wherein the guide rods come to lie on both sides, between the two wings. Around the guide rods are two mainsprings. Through this construction the massive mainspring of the grenade rifles has been replaced by a smaller and more easily manageable double spring. The designers were apparently not sure that this double mainspring could adequately dampen the massive recoil, so they included an extra friction brake. The top of the tailpiece has an elongated slot with three circular cut-outs. In these cut-outs rest three springs and on top of those lies a steel block; a friction-resistant material (probably asbestos). The springs press that block against the inside of the housing. With the recoil of the barrel and breech, the friction between asbestos and housing creates an additional delay. If all this was not sufficient, then there was the unique butt plate. Between the wooden butt plate and its metal mounting are two heavy coil springs, to spare the shoulder of the shooter.

Just as with weapon number 10, the wooden handles of this weapon resemble closely those of the vz. 26. In this case, however, they are newly created with some minor adjustments. To tilt the barrel open, a kind of trigger in front of the front pistol grip must be pressed, after which the pistol grip can pivot inward. The narrowed upward section of this grip pushes the barrel open when it is pressed inward. The ejector, a bridge piece fitted with two axes in the rear part of the barrel, then springs out.

The trigger mechanism is a simplified version of that of the ZK 424. The trigger has a U-shaped extension, which keeps the firing pin cocked. When the trigger is pulled, the front of this extension pivots downward and releases the firing pin. A sliding plate functions as a safety. In its rearmost position, a tongue on the plate covers the extension and blocs its movement. This “safety catch” has no markings.

Gewehrgranaten-Büchse 11 has a similar grenade sight on the left side of the housing as number 10 and number 7, with the same flaws: Only if the weapon is held at an angle greater than 45 degrees can you use the front sight by looking underneath the front pistol grip.

Shutdown

On July 14 and 15, 1944, the Special Committee on Infantry Weapons officially held its first meeting in Berlin. During the meeting, all weapons projects on the list of April were scrutinized. Most of the developments were stopped. This included the construction of a Gewehrgranaten-Büchse in Brno. It marked the end of this fascinating development.

If one looks at the weapons from an engineering point of view, one quickly gets the idea that there were two different (teams of) constructors; one designing the relatively simple tilting barrel weapons, and the other for the much more complicated guns with rotating barrel. In the absence of concrete information, there is unfortunately not much more to say. Production numbers, planned deployment, the type of ignition cartridges; all remain unclear. Apart from that, we are of course delighted that these four unique weapons can be shown. And maybe the story will have an ending just for submitting this article as we learned that there are two or three more Gewehrgranat-Büchsen in the museum in Prague.

(Thanks to Jan Skramoušský of the Vojenský Historický Ustav (VHU) in Prague.)