Another very interesting weapon chambered for the.22LR cartridge was our Soviet Blum machine gun. It didn’t have the phenomenal rate of fire of Richard Casull’s American submachine gun, and he didn’t need it. But it contained in its design many unusual solutions that make it truly unique, and one of a kind, so that it, perhaps, can even be called a "work of weapons art."
One of the variants of the Blum training machine gun.
Well, the story about him should begin with the fact that in the period between 1918 and 1939 the machine gun became the basis of the infantry's firepower. All infantry tactics were now built around him. And the command of the Red Army, realizing this, has been constantly increasing the number of Maxim machine guns in the troops since the mid-1920s. Then, in 1927, the Degtyarev light machine gun was added to it, which began to be attached to each infantry squad. So the number of machine guns in the army was increasing all the time, which meant that people who were able to shoot accurately from them had to be trained on something!
But in the country there was a strict economy regime, so the industry was not able to learn how to fire live ammunition. After all, not only cartridges and gunpowder were spent in this case, but also the resources of the barrels and mechanisms of military weapons. We needed training grounds and shooting ranges, and all this required money, money, and more money.
A way out of the situation could be the use of low-power small-caliber rimfire cartridges, which occupied an important place in the Red Army in the system of pre-conscription training. Small-caliber training revolvers, pistols and rifles were created and produced for them. The difference in bullet ballistics was compensated for by a decrease in the size of the targets and a decrease in the firing distance to such a distance at which the data of the small-bore bullet corresponded to the trajectory of the bullet of the live cartridge. That is, in addition to the existing arsenal, it was necessary to create a small-caliber machine gun for training personnel and the same pre-recruits!
The matter, however, was complicated by the fact that the creation of an automatic weapon chambered for the "small" is a very difficult task because of a number of features of such weapons. First of all, you need to provide a simple and reliable way of supplying it, so that automatic fire from it could be fired for at least 3-4 seconds. It is clear that single-row box magazines for 5-10 rounds, used in such weapons, were not suitable for a machine gun at all. But there were other requirements that M. N. Bloom, his designer, described it as follows:
b) maximum simplification of the cartridge kinematics;
c) simplicity of the feed mechanism, otherwise, even with a slight deterioration in working conditions (pollution, low temperature, etc.), delays will be inevitable;
d) the minimum energy consumption of the moving parts for the action of the feed mechanism.
Cartridge.22LR (5.6mm)
All these tasks were solvable. Basically! But in reality, technically, they were not easy to solve. The fact is that the sleeve of this cartridge is made of thin, easily deformable brass, but at the same time it has a rim at the base containing a primer composition. Therefore, even a not-so-strong off-axis impact at the moment the cartridge is fed can cause it to detonate ahead of time, which will lead to injury to the shooter and damage to the weapon. Well, the presence of a rim always complicates the work on the store. Especially if it has a large capacity. A bullet made of soft lead does not have a shell at all and can be easily deformed upon contact with parts of the feed mechanism. And such deformation can significantly worsen the accuracy of the battle. And then it keeps very weakly in the sleeve. So weak that the cartridge can be easily broken with your fingers. Therefore, in "small-sized weapons" it is better not to use those ramming systems that increase the likelihood of unloading, and there are quite a few of them.
And the fact that the designer managed to overcome all these difficulties speaks of his considerable talent and design savvy.
The first machine gun M. N. Blum designed it back in 1929. It was designed to be installed inside the Maxim machine gun, instead of its standard mechanism, and therefore received the name "liner machine gun". It had the dimensions of the Maxim's receiver, but the rate of fire was clearly excessive - 3,500-4,000 rounds per minute. Therefore, a retarder of the rate of fire was introduced into the design, giving 450-800 rds / min, however, the price of the solution was to complicate the design of the weapon. The automatic machine gun operated on the basis of the recoil of the free breechblock, and the ammunition supply came from a rack with sockets for 25 rounds. The trigger mechanism made it possible to shoot both single shots and bursts. It is interesting that when the machine gun was inserted inside the Maxim's box, a complete illusion of the machine gun's operation was created during its combat use. But it did not go into mass production, since Blum in 1930 created an even more perfect version, but not in the form of an insert in the machine gun box, but an installation that was reinforced on the "Maxim" from the right-top. The receiver of this machine gun was long, which gave a longer run to the bolt and, accordingly, reduced the rate of fire and the required 600 rds / min.
On the basis of this machine gun, variants were developed that replaced the tank, manual, aviation and other types of machine guns in service with the Red Army. All of them were very widely used for the preparation of machine-gun crews, which made a significant contribution to strengthening the country's defense in the pre-war period. Blum himself wrote about it this way:
“Small-caliber machine guns are able to replace military weapons in all types of training machine-gun firing without exception, including shooting from closed positions, shooting at moving targets, etc. On a small-caliber machine gun, you can practically train a machine gunner, starting with the basics of machine gun business and ending with the execution in a field situation (distance 200-300 m) of complex machine-gun tactical tasks with shooting at figured targets of normal size."
He also designed a small-caliber "carbine-machine gun", which was a training version of a submachine gun. It had a simple wooden stock and a barrel 400 mm long.
Blum was an experienced hunter and suggested using this weapon as a hunting carbine. Experiments with him have shown that bursts of 5-8 shots are the optimal type of fire. At the same time, the bullets fell very closely and created an effect similar to the hit of buckshot from a 12-gauge shotgun. Blum offered his carbine-machine gun for hunting birds and small animals, such as wolves. And he was absolutely right! After the war, his decommissioned machine-gun carbines were transferred to hunting farms, where they began to be used to shoot wolves from aircraft, which was both an effective and safe means of controlling their population.
Blum machine guns on Maxim machine guns.
It was proposed to use this weapon as a basis for the development of mass machine-gun sport in the country (that's how it is!), Which would become a serious component for pre-conscription training of young people within the framework of the OSOAVIAKHIM system.
In 1933, the Kovrov Instrumental Plant No. 2 (now the VA Degtyarev Plant) produced 33 Blum machine guns, in 1934 - 1150, in 1935 - 1515. In general, Blum's machine guns played a significant role in the training of machine gunners in the Red Army and saved the country a lot of valuable resources.
As for the design of the Blum machine gun, the most original in it was his store. And so there was nothing special about it. Shooting from a free shutter, the trigger is connected to the trigger on the machine gun. But there were options with a conventional trigger. As for the 40-round magazine, it was essentially a revolving drum with cartridge slots. Moreover, when the magazine was inserted into the machine gun, each successive socket of its internal cartridge disk turned out to be alternately in front of the chamber when firing, becoming its continuation, so that the cartridge in it could only move forward. By the way, he also did not touch the neighboring cartridges and did not experience any deforming effects. The bolt moved through the cartridge socket in the disc in such a way that it sent the cartridge into the chamber, and then, with the help of two strikers, struck the capsule and fired a shot. Then the pressure of the powder gases threw the bolt together with the sleeve back. The sleeve was thus found in its nest and was preserved, and the disk was further rotated by 1/40 of its circumference, after which the next cartridge stood in front of the chamber. Usually, 39 rounds were loaded into the store, since one slot was left empty, since the shooting took place from an open bolt, and there were no fuses on the machine gun. Well, then the 40th cartridge could easily fall out of the store through the hole in the cover of the store, because there was nothing holding it there.
Store device.
The front part of the bolt was a long thin rod with two strikers on the front cut, which passed through the magazine and fed cartridges from it "asking for". The rotation of the cartridge disk of the store was carried out using a ratchet mechanism driven by the movement of the shutter back and forth.
Shop details.
There was no ejector or reflector, and the spent cartridge case was extracted due to the residual pressure of the powder gases remaining in the barrel bore. For unloading in the event of a misfire, a cartridge or a stuck spent cartridge case was removed by removing the magazine with a manually operated ejector from a button under the barrel of the weapon.
