Sunday, 15 May 2016

World of Tanks History Section: Rifle Grenades

The range of a hand grenade is very short. In WWI, many methods were tried to solve this problem. One of those was a special rifle grenade. A cup was attached to the muzzle of a rifle, which fired a grenade with the aid of a blank cartridge. This method was not very effective: the range was barely a few hundred meters, the fragmentation effect of the grenade was weak, and there was no accuracy to speak of. Due to a low muzzle velocity, the shots had to be fired at a large upward angle. Despite poor reliability and questionable effectiveness, the idea of rifle grenades not only survived until the Great Patriotic War, but continued to evolve.

A design of a supercaliber rifle grenade.

Competition Over Nothing

At the start of the Great Patriotic War, two design bureaus worked on rifle grenades: KB-30 and A.K. Serdyuk's SKB-35. In November of 1941, grenades from both organizations were tested at the Small Arms Research Proving Grounds. Serdyuk's VPGS-41 grenade was already in service with the Red Army. The KB-30 design was experimental.

Trials showed that the VPGS-41 reliably penetrated 20 mm of armour. However, there was a significant drawback: the stabilizing fins fell off the grenade more than half the time. The testers recommended that the design should be improved and gave Serdyuk until February of 1942 to do it. By then, he had to provide a new test batch of 500 units.

Serdyuk's rifle grenade and its usage.

The KB-30 grenade, which used a small cup to fire, penetrated less armour, but proved to be a lot more stable. The army ordered ten times more grenades of this type than the other to send them to trial in combat. Since the grenade was never accepted into service, one can only assume that the results were unsatisfactory.

Meanwhile, Serdyuk's design bureau also hit a snag with their grenades. Complaints about low effectiveness, reliability, etc. poured in from the front. The designer tried to stand up for his brainchild, sending a letter to the Chair of the Artillery Committee, Major-General Hohlov on June 6th, 1942, citing production problems.

"Insufficient technical guidance and military representative control resulted in significant deviations from blueprints and technical requirements, which mostly resulted in the following: haphazard choice of materials (whatever was available), incompetent heat treatment, a lack of anti-corrosive coating, large dimensional deviations, replacement of type 41 gunpowder with VT gunpowder, etc.
I can say with certainty that no type of ammunition is built as poorly as VPGS-41.
The use of the VPGS-41 grenade on the front caused negative feedback, which was mostly caused by the chaos during production that I mentioned above. 
The humble ballistics of the grenade (low muzzle velocity and range) were further compromised by poor quality of manufacturing, causing torn off stabilizers, misfires, fouling (a result of using VT gunpowder instead of type 41 like in the original design), etc.
I must add that there are also such negative occurrences as a lack of well though out tactics, means of storage and transport, and no training on how to use the grenade."

Investigating the situation, high command understood that improvement in quality was not possible in 1941-1942, and the VPGS-41 along with its more powerful 42 version was removed from production.

Even well regarded specialized design bureaus had trouble with rifle grenades. What happened when amateur inventors and other design bureaus tried their luck?

From Kazan to Leningrad

In April of 1942, a letter arrived at the People's Commissariat of Defense from the deputy director of the Physical Institute of the Academy of Sciences of the USSR, B. Vule. He wrote that the institute was about to start development of finned rifle rockets. These rockets would fly along a flat trajectory to more accurately strike enemy tanks. The estimated mass of the grenade was two kilograms.

The response from GAU specialists said that the development would make sense if the trajectory of the rocket at 200 meters was lower than the height of a tank and that the dispersion at that range would be less than a square meter. Since the letters stopped there, one can assume that the Kazan physicists could not meet these requirements.

Engineer Lipkovskiy from Moscow took a mortar round as a foundation for his anti-tank grenade. His idea was rejected on the basis that it had no advantages for the VPGS-41 grenade, but the recoil could easily injure the shooter.

Another type of anti-tank rifle grenade were bottle launchers. As the name implies, they would fire bottles of incendiary fluid at the enemy. The best known model was developed by Zuckerman, and a small batch was produced in blockaded Leningrad. Other variants sent to GAU were rejected with the standard reasoning of poor accuracy.

How to Kill an Anti-Tank Rifle in Ten Shots

One of the most interesting projects was tested at the Gorohovets proving grounds in the fall of 1943. This grenade launcher consisted of a Degtyaryev anti-tank rifle converted to fire 50 mm and 82 mm mortar rounds, converted to supercaliber grenades.

"Before beginning the trials, the Gorohovets ANIOP warned the inventor comrade Starikov about the possibility that the rifle will burst due to the large weight of the mortar round in comparison to a bullet. At his instruction, the trials went ahead anyway.
The firing was done with a 14.5 mm Degtyaryev anti-tank rifle. It was angled at 45 degrees when firing, resting on the ground in three places (the stock and the bipod). A piece of rubber was placed under the stock to soften the shock.

At the start of the trials, a test shot was made with a stock 14.5 mm armour piercing bullet at full charge. The stability of the rifle was not impacted by the shot. 

After the test shot, a shot was made with an 82 mm fragmentation round Type B (with a movable stabilizer), with a 500 mm long rod with a full 0,035 kg load of 4/7 gunpowder. After the shot, the rifle barrel was torn apart, with the front part of the barrel found 5-6 meters in front of the rifle. The remaining part of the barrel had a 500 mm long tear."

A week later, lighter 50 mm rounds arrived at Gorohovets. Meanwhile, the rifle was repaired, with the damaged part of the barrel removed and the remainder reinforced. The muzzle brake was screwed onto a non-reinforced barrel section. This time, the rifle survived to make eight shots, which sent the rounds to a range of 500-700 meters. The muzzle brake fell off on the first shot, and each shot destroyed some more wooden elements of the AT rifle. Having expended all of his 50 mm rounds, the inventor decided to try an 82 mm one. The round travelled for 400 meters and the rifle turned into scrap: the loading mechanism and attachment of the body to the stock were destroyed.

Even though trials were not successful, they impressed the testers. In 1944, another attempt at a supercaliber weapon was made. Right at this time, an incomplete captured German grenade launcher was brought to Gorohovets, along with several rounds of ammunition.

Ivanov and Bazeyev's rifle grenade.

"In the beginning of the current year, elements and assemblies of a captured German anti-tank grenade launcher from the Ukrainian Front were delivered to the ANIOP. In addition to the elements and assemblies, several HEAT grenades were included. Since the grenade launcher was not complete, it was not possible to assemble it for trials. In addition, this type of grenade launcher was not described in informational materials, and its combat effectiveness is unknown. 

In order to study the captured weapon to obtain data suitable for domestic designs, a technical project was made and a similar grenade launcher was built. The stock and breech of a Berdan rifle were used in the design.

The few grenades present at ANIOP were disassembled to study their design, so new grenades had to be produced to test the weapon. Due to a high load on the ANIOP mechanical workshop, the grenades were not produced and the grenade launcher was not tested."

Engineer-Colonel Ivanov and proving grounds worker Bazeyev took a stock and a breech from a Berdan rifle and assembled a grenade launcher that could theoretically use German grenades. While they were working, the captured rounds were disassembled for study. There was nothing to shoot with.

The designers asked to manufacture their own grenades, but GAU decided to not waste their resources. This was 1944, not 1941, and it was the Germans' turn to hurriedly invent the next anti-tank wonder weapon.

Original article available here.

1 comment:

  1. I daresay the opening paragraph is selling rather short a weapon system that was already quite mature and effective by the end of the Great War - the trenches were highly Darwinistic to ideas that didn't work out right. The ensuing worldwide adoption and further R&D of the concept right up to the present day also suggest soundness.

    The writer also seems to be somewhat confused of the tactical purpose of the whole thing. The intent is to project useful amounts of (usually explosive) payload out to tactically useful ranges past what mere strong throwing arm can supply, without the added encumberance and hassle of a dedicated support weapon. If you need to reach past *that*, bring a proper mortar or call the artillery already.

    Underbarrel grenade launchers, also rather widely popular, are another means to the same end with different pros and cons.