Blum antitank rifle model 1942
In the mid-1930s, the USSR launched large-scale work to create anti-tank rifles. Among other developers and was Soviet designer MN Blum.
MN Blum in creating PTR were held jointly with SV Vladimirov. In April 1937, on the NIAP among other two options were tested guns Blum-Vladimirov under 20-mm automatic gun cartridge model 1930, differ in that one had a bipod, and the second was installed on the machine. There was a simplicity and durability of automation, as well as the lack of armor and heavy weight construction. These guns have a lot of 42 and 83 kg, respectively, the total length of 1405 mm, the initial velocity of the projectile 861 m / s and rate of 20 rounds per minute.
In 1937 and 1938 Blum developed two variants of anti-tank rifle, respectively 12.7 mm cartridge with an under-reinforced high-speed bullet and a standard cartridge 12,7 x108 from the ANC. These guns had total weight 28 and 26 kg, respectively, the total length of 2030 and 1610 mm, muzzle velocity 1018 and 747 m / s. These samples did not pass the test because of low survivability trunks danger of moving parts (in one case over the back arrow in the other case in his face) and the lack of the required sight.
During World War II appearance in German tanks with thicker armor forced designers to find a way to increase piercing PTR. The work was conducted in two directions - "relieved" PT guns and "consolidation" PTR. Found a number of clever solutions and create an interesting design. Among them, a large interest has single-shot anti-tank rifle design MN Blum developed it in 1942.
PTR Blum model 1942 has been designed by a specially crafted based on the liner 23 mm aircraft cannon shot cartridge caliber 14.5 mm (14.5h147). The new cartridge allowed to give an armor-piercing bullet initial velocity of 1500 m / s.
gun was singly charged, was rolling shutter with turning during locking. Locking by two symmetrically arranged lugs, located in front of the gate. Impact mechanism striker type, rotating bolt cocked when unlocking. Safety mechanism was absent. Trigger consisted of the trigger and the gear lever, the sear tripping striker who is in seclusion. Reflection of spent cartridges carried sprung reflector located in the gate.
Sights were made to the left and are designed for firing with a constant eye.
To reduce the impact on the front end of the barrel muzzle brake is set, and the butt plate is placed on a felt cushion, armrest.
gun was supplied with folding bipod and pistol grip fire pistol.
In August 1943, the Red Banner courses "The Shot" was tested antitank rifle Blum and PTR RES. The 100m RES antitank rifle pierced the armor up to 70 mm, the system Blum - up to 55 mm at a distance of 200-300 m both systems pierced the armor up to 50 mm. Commission testing anti-tank guns, said: "By the power and armor-piercing effect of both the test specimen and MFR MFR RES Blum far exceed the armament PTRD and PTSD and are certainly reliable means of struggle vs. tank type T-IV and even more powerful armored vehicles enemy ».
But by that time it became apparent that in an ever-increasing armor of tanks and self-propelled guns antitank rifles were becoming less reliable means of dealing with them. Not unimportant role played extremely high pressure in the barrel, which led to his rapid deterioration. As a result, Blum PTR model 1942 on arms had been taken into production and not received, remained a prototype.