Differences Between the VZ-58 and the AK

First, I'd like to wish all the readers of this blog a very happy 2015.

Quick, identify the firearm in the image below:

Click on the image to enlarge. Public domain image.

If you said something along the lines of "AK-47" or "AKM", then you're wrong. What you're looking at is the Czechoslovakian vz. 58 rifle. The vz. 58 does resemble an AK-47 or an AKM externally, but there are a lot of differences underneath the hood. We will study more about this rifle in this post.

The name "vz. 58" is actually a contraction of "vzor 58' (i,e. "model 58"). The official full name of this weapon is "7,62 mm samopal vzor 58" (i.e. 7.62 mm. automatic firearm model 58"). The number 58 is because this weapon entered service in the year 1958 (the AK-47 is named similarly -- it first entered service in 1947).

After World War II, the Soviet Union started using the 7.62x39 mm. cartridge for its AK-47 and AKM rifles and insisted that all the Warsaw Pact countries use the same cartridge for standardization. Many of the Warsaw pact countries (Poland, Hungary, Romania etc.) adopted the cartridge as well as the AK rifle for their military forces, but the Czechoslovakians decided to only adopt the cartridge, but use their own rifle technologies. They already had a history of developing firearms for 300 years or so, and the city of Brno was most recently known for developing the precursor to the famous Bren gun of World War II. A designer named Jiri Cermak was assigned to develop the new rifle in Brno in 1956 and the new rifle entered service in 1958.

The new rifle was chambered to use the 7.62x39 mm. cartridge, the same as the AK-47. This is about where the similarity between the two ends. What are some of the major differences?

• Action: The AK-47 (and AKM and the rest of the AK family) uses the long stroke piston system, whereas the vz. 58 uses the short stroke piston system. In the short-stroke system, the piston moves for a very short distance (in the case of a vz. 58, it moves 19 mm. (or about 0.74 inches)), whereupon it is stopped by a projection. The short backward movement of the piston imparts a sharp blow to the bolt-carrier, which separates from the piston and then continues backwards due to momentum. In a long stroke system, the piston and the bolt carrier move backward together. This means that the short stroke piston system has a smaller mass of moving parts, since the bolt-carrier weighs less than the combined bolt-carrier and piston together. Therefore, there is less vibration and balance shift due to the moving parts and the vz. 58 is easier to keep pointed to the target.
• Firing mechanism: The AK-47 uses a traditional rotating hammer mechanism, whereas the vz. 58 is striker fired.
• Safety/Fire selector lever: The easiest way to tell if a rifle is a vz.58 or an AK is by looking at the fire-selector lever. The AK-47 family is famous for its clunky large fire selector lever, which is located on the right side of the weapon above the trigger and is cumbersome to operate. The user needs to take the firing hand off the pistol grip to manipulate an AK fire selector lever. The vz. 58 has a smaller, much more ergonomic selector mechanism and the lever can be manipulated without taking the hand off the pistol grip. The following two pictures show the differences (click on the images to enlarge -- the fire selector levers are enclosed in red ovals in the images below):

AKM fire selector lever. Note the length of the fire selector lever and its position relative to the pistol grip.
Click on the image to enlarge.

vz.58 fire selector lever. Notice how it is positioned close to the pistol grip and can be easily manipulated.
Click on the image to enlarge

• Magazine: The AK-47, AKM and vz. 58 all come with 30 round box magazines, however, the vz. 58 magazine is shaped a bit  differently, so it cannot be inserted into an AK and vice-versa. The vz. 58 magazine is also made of a lightweight aluminum alloy and therefore, it is lighter than the steel magazines of the AK family. The vz. 58 magazine can also be loaded via stripper clips, without removing the magazine from the rifle.
• Receiver: The early AK-47 receivers were made of milled steel, until the Soviets mastered the art of producing stamped steel parts from the Germans and the AKM (and all subsequent AK models) all have stamped steel parts. This was done to improve the production rate. The vz. 58 still uses a milled steel receiver. While it takes longer to make a milled steel receiver, it is more rigid and therefore has a bit more accuracy.
• Lock action: The vz. 58 has a tilting lock action with a falling breechblock (similar to Beretta 92)
• Bolt hold-open feature: When the last round has been fired in a vz. 58, the bolt catch locks the bolt carrier to the rear of the gun and it stays open, which alerts the user that the firearm is empty. In an AK, the majority of the magazines allow the bolt to go forward on an empty magazine, therefore, the user cannot easily tell that the rifle is empty.
• Stock: The early vz. 58s were made using beech wood stocks, but they soon switched to using a wood-impregnated plastic stock. If you click on the image of the rifle above to enlarge it, you'll notice that the stock has a somewhat grainy look to it. These stocks are affectionately known as "beaver barf" to collectors and are light, durable and economical. AK rifles use laminated wood stocks (earlier models used normal wood and later models use plastic), which are also durable and cheap to produce, but they are a bit heavier. Later stocks on vz. 58 were made of steel and alloys and designed to be foldable or collapsible. One more difference is that the stock on a vz. 58 is designed to be modular and easily detachable/interchangeable.
• Dust Cover: The receiver on a vz. 58 has no ejection port dust cover, because the receiver is completely enclosed by the bolt carrier. Therefore, the ejection port is huge compared to an AK. This can be easily seen when the rifle is being operated. 
• Disassembly: The vz. 58 is held by two pins and is designed to be disassembled without using any tools.

Even though the AK family and the vz. 58 look very similar externally, the vz. 58 cannot exchange parts with the AK family because of the vast differences in the mechanisms.

The following video makes the differences between the two very clear.

The vz.58 was manufactured between 1958 and 1984 and around one million rifles were manufactured, which means they are not as widespread as the AK family. They still remain in use with Czech and Slovak military forces, and they were exported to some other countries as well (Cuba, Vietnam, India, Indonesia, Ethiopia, Uganda etc.)