Sturmgewehr 45 assault rifle (M).
Today, wherever you look on the Web, the following text takes place: "The first samples used automation based on a gas engine and rigid locking of the barrel with a pair of rollers, similar to that of the MG 42 machine gun, but the scheme was too complicated." And now let us re-read this passage again and ask ourselves the question, what ignoramus (you will not find another word!) Wrote all this? Well, what kind of gas engine did the MG 42 have when this machine gun works on the principle of barrel recoil with its short stroke? Now we read further: “Before firing, the bolt under pressure from the return spring is in the extreme forward position, forcing its front beveled part of the rollers from the bolt into the grooves in the barrel sleeve. At the moment of the shot, the combat larva begins to move backward under the pressure of the powder gases to the bottom of the sleeve. The rollers installed in the larva are dragged behind it, pressing into the bolt and forcing its beveled front part to move backward relative to the combat larva. The main energy of the powder gases is spent on accelerating the most massive bolt. By the time the pressure in the barrel drops to acceptable values, the rollers are completely "retracted" into the bolt, after which the entire bolt group moves back, removing the spent cartridge case and feeding a new cartridge into the chamber on the way back " … Surprisingly, everything that is written and highlighted here is written sufficiently correctly and … incorrectly at the same time.
Czech poster depicting Sa vz. 58.
The vz. 58. At the bottom left, you can clearly see what parts the bolt group consists of. On the right is the device of the gas venting mechanism.
It would be more correct to write that for this sample of the machine, the shutter consists of two parts (or parts) - upper and lower, which, if desired, and by virtue of tradition, can be called a combat larva. The British call this part the bolt head and it seems to me that this is more correct. Then we have the top and bottom of the shutter and this bottom has a head. There are two rollers in the head. The upper and lower parts of the shutter are movably connected. But there is no "beveled front part of the shutter". There is a rod through which the striker passes and which enters the larva (lower part), and this rod has lateral bevels in its profile, and they, when it pushes into the larva, really presses on the rollers and pushes them into sides. But the rollers themselves are not retracted into any shutter. They are removed inside the combat larva, or in the lower part of the bolt! Its upper part is really massive, cylindrical in shape and is connected to the return spring rod. In the lower part of the combat larva there are two protrusions that slide along the grooves of the receiver. Therefore, the shutter moves strictly horizontally. By the way, the grooves for the rollers are also made in the receiver.
Soldiers of the Czech army with machine guns vz. 58.
CZH 2003 Sport. Limited production in Canada. Option with a barrel extended to 490 mm.
Right view. Maple Leaf is the mark that this model was manufactured in Canada.
Then everything seems to be clear. When a shot occurs, the powder gases press on the bottom of the sleeve, and through it on the combat larva. To facilitate the operation of the mechanism, in the place where the threaded part of the barrel begins, there are grooves (Revelli grooves) that divert part of the gases to the walls of the sleeve, which ensures its better extraction. And, yes, when the gas pressure in the barrel drops to an acceptable value, both rollers are recessed in the larva and it, together with the bolt, moves back, and then moves forward again by force due to the force of the spring.
Standard army model. Left view.
Standard army model. Right view.
However, nowhere is it written, why then such a massive, even seemingly metal casing on the barrel is needed. After all, it turns out that all the automation is in the receiver! So why is the Sturmgewehr 45 (M) also a "decoration"? But why: the gas outlet mechanism is hidden there! The hole in the barrel is closed by a spring-loaded rod. But the most interesting thing is that this rod is not connected with the shutter in any way, but only serves to relieve excess pressure and the barrel. Well, gases come out from three holes on top of the lid. I wonder why no one wrote about this interesting feature of this machine? Didn't know what was hidden under this cover and how it works ?!
This is the look of the bolt group when retracted. The extractor and striker are clearly visible. Please note that the front of the receiver does not have a cover. The shutter closes it.
And this is the elongated barrel of the Canadian model.
Further, everything that they write is quite acceptable: the trigger on it is really a trigger type, which makes it possible to fire both single shots and bursts. The firing mode translator (and also the fuse) is located on the left of the receiver, as is the bolt handle. The stock is wooden and is located in line with the barrel in a "linear pattern", which reduces the barrel toss, but forces the sights to be raised high above the barrel. By the way, it is also bad that they on Sturmgewehr 45 (M) are too shifted forward and far from the shooter's eyes. It would be necessary to place them on the back of the receiver cover, but for some reason the Germans did not. It turned out that due to the long sector magazines for 30 rounds, there was a problem with an increase in the profile of the shooter when shooting prone, and in order to solve it, a special shortened magazine with a capacity of 10 rounds had to be developed for the rifle.
Forend and receiver pad.
And this is how they are removed. Interestingly, the mounting pins are not fully removable, so you cannot lose them!
Well, then the German engineers who took part in the creation of the StG45 (M) found shelter in France and began working for the French arms company CEAM. From 1946 to 1949, Ludwig Forgrimler and his colleague Theodor Loeffler created three versions of the new machine for.30 Carbine, 7, 92 × 33 mm and 7, 65 × 35 mm cartridges. France eventually received the CEAM Model 1950 assault rifle, and Forgrimler, already in Spain, working for CETME, designed the CETME Modelo A rifle. Subsequently, it was the StG 45 that served as the basis for the HK G3 automatic rifle, which appeared in Germany in 1959, and the submachine gun HK MP5, while in Switzerland, the SIG SG 510 rifle began to be produced in a similar pattern.
Gas piston.
Gas piston extended from the gas tube.
And here's an interesting question: did the Czech designers get acquainted with this weapon or not? In any case, the system with a piston on the barrel was known to them, and they implemented it in their vz. 52 rifle. How about a roller retarder? In any case, one thing is certain: when in 1951, engineer Jiri Cermak from Brno began work on his machine gun, he borrowed a lot from other small arms models known at that time, but in the end he tried to go his own way. Of course, he knew the Kalashnikov assault rifle. But … somehow the design of the Czech designer did not satisfy.
One of the features of vz. 58 is the presence of two springs - a returnable bolt - it is at the top, and a combat one - a drummer, it is at the bottom.
He worked hard, hard and consistently. First, he developed the ČZ 515 assault rifle for the Czechoslovak cartridge 7, 62x45 mm vz. 52. It had a shortened barrel from a vz.52, which fired from an open bolt (this was the requirement of the army, which feared spontaneous ignition of cartridges in the chamber during intensive firing), and a trigger mechanism with a trigger from the German MG 34 machine gun, which, depending on the pressure on the upper or lower part of it, included either a single or automatic fire.
Fully assembled automatic shutter.
During the tests of the assault rifle, it was found that the ČZ 515 did not meet the accuracy requirements for weapons by the Czechoslovak army. It was believed that the reason was that the fire was being fired from an open bolt. Then Chermak made the ČZ 522 assault rifle, which had the same trigger, but firing was fired from a closed bolt, and the gas valve had a gas piston acting on the bolt. In 1954, the ČZ 522 and two other prototypes (from rival design groups) were tested by both the Czechoslovak army and the Soviet army in the USSR. During this testing, Soviet specialists found that all three machines needed improvement, but the ČZ 522 among them was considered the best.
Bottom view of the shutter. The striker rod with longitudinal grooves and the swinging larva with protrusions are clearly visible.
The third version was also initially planned for its own, Czechoslovakian cartridge, since it had previously been used in the Vz. 52 and in a light machine gun with the same designation. But in the USSR, it was considered necessary to standardize the small arms of its allies in the ATS, so the prototype of the "Koště" assault rifle (that is, in Czech "Broom") was made under the Soviet intermediate cartridge 7, 62 × 39 mm M43, used in the SKS carbine and in Kalashnikov assault rifle. In 1958 he was given the designation Sa vz. 58 and adopted by the army of Czechoslovakia, after which over the next 25 years more than 920 thousand copies were produced. The assault rifle entered service with the armies of Czechoslovakia, Cuba, as well as a number of countries in Asia and Africa.
The lower part of the bolt with a swinging U-shaped larva put on it.
True, the initial sample of the assault rifle weighed 3.2 kg, which was more than the weight set by the army and equal to 3 kg. Then an aluminum alloy magazine was developed for him, which achieved the desired weight reduction. By the way, even the weight of the AKM assault rifle was greater than the original weight of the Chermak assault rifle. True, the designers had to tinker with the problem of spontaneous ignition of cartridges in the chamber during intensive shooting, which usually occurred at 180 rounds. However, it was eventually resolved.
Firing pin extended from the bottom of the bolt.
The assault rifle was arranged in a rather original way and only outwardly resembled a Kalashnikov assault rifle. Chermak did not begin to abandon the gas engine, but his gas piston has nothing to do with the shutter. It has its own return spring and when fired, it strikes the bolt carrier with a strong blow, pushing it back. By the way, this phrase found on the Internet - "To provide the required push to the bolt group, the piston could move only a few centimeters" - does not correspond to reality, or rather not very accurate. The piston moves back only 19 mm, while the bleeding of powder gases occurs after a passage of 16 mm.
The bolt group (this is the best name for this set of parts) consists of a bolt carrier with a reloading handle (or the upper part of the bolt group), a lower part, a swinging U-shaped larva and a striker with longitudinal grooves. And it is precisely this swinging larva in the lower part of the bolt that plays the main role in the barrel locking system. When the piston hits the bolt carrier and throws it back, it moves 22 mm (while only the upper part moves back, and the lower one still locks the barrel bore!) And here the wedge-shaped surface of the bolt carrier presses on the larva, which makes it disengaging with receiver protrusions. The lower part of the bolt group rises up, moves back together with the upper one, as a result of which the spent cartridge case is ejected and the drummer is cocked.
The stock of the model CZ858.
As for the firing mechanism, then, yes, it is a striker type. The striker is located inside the lower part of the bolt group with an ejector, and behind it is a twisted combat spring, which is put on a rod in the rear wall of the receiver. There are grooves on the striker so that it can move along the guides inside the above-mentioned part. From below, there is not a tooth on it, which engages with the sear when the weapon is put on a combat platoon. There is no striker on the drummer. He only hits him during each shot, and the firing pin is in the lower part of the bolt carrier.
That is, in principle, the gas venting mechanism was not needed. A short barrel travel or roller deceleration, like the Sturmgewehr 45 (M), would be sufficient. But a bayonet was needed, so the barrel was fixed rigidly.
Aim.
The sights of the assault rifle consist of a front sight and an adjustable rear sight, which allows hitting targets at a distance of 100 to 800 m in increments of 100 m, both in daylight and at night.
Shop.
The assault rifle was equipped with box-shaped sector magazines for 30 rounds of light plastic. After the last shot, the shutter remained open until a new magazine was inserted. The magazine latch was located on the left at the base of the receiver. The ejector is at the base of the magazine receptacle. It was possible to use clips for 10 rounds (similar to those used in the SKS). At the same time, the stores vz. 58 are incompatible with magazines of the AK family.
The neck of the store.
The stock, grip and forend were first made from wood, and then from an unusual material - plastic mixed with wood chips! A bayonet-knife could be attached to the machine gun, and on some samples also a bipod and an under-barrel grenade launcher. Weapons made in Czechoslovakia were distinguished by their traditionally high quality of workmanship. All parts of the bolt, the gas piston and the bore were chrome-plated, and the outer surfaces of the metal parts were phosphated. In addition, they were coated with a special varnish to protect against corrosion.
One of the options for upgrading vz. 58.
Automatic vz. 58 was equipped with various accessories: for example, two-way fire translators could be installed on it, the forend could have a different configuration, muzzle brakes and compensators could be put on the barrel. All this was installed on both military and civilian models of the machine: soldiers from various private military companies were usually equipped with such accessories. The machine also sells four spare magazines and a bag for them, a bayonet with a scabbard, a cleaning brush, a muzzle cap, a bottle of gun oil, a unified strap, a sight adjustment tool, a bipod and a device for firing blank cartridges.
