Saturday, 27 July 2019

Kalashnikov and the Intermediate Round

After an unsuccessful attempt at a submachinegun and light machinegun, the young small arms designer Mikhail Kalashnikov did not lose hope, but began to design a new semiautomatic carbine for the new intermediate round. However, here too he was faced with defeat. Why did it happen, and what lessons did the future author of the AK learn from this?

Designing blindly

As mentioned many times, the biggest issue in the creation of a light machinegun that faced Soviet gun designers was the 7.62x54r designed for the model 1891 rifle. It was modern for its time and worked well in bolt-action rifles, but its characteristics were far from optimal for automatic weapons. V.G. Fedorov wrote about this in the early 20th century.

Discussions about replacing the old round with something more modern started about that time. While this would be an easy task for an industrialized nation with a small army, the Russian Empire had a weak industry and a very large army, and could not find a good time to do it. The USSR also could not make this leap in the interbellum period.

7.62x39 intermediate cartridges.

Inspection of the American M1 carbine received as a part of Lend Lease did not change matters. GAU specialists remarked that "increasing the muzzle energy and velocity of the pistol bullet does not give any noticeable effect".

However, an analysis of a captured MKb.42(H) "automatic carbine" in the summer of 1943 had a different result. A Wehrmacht armed with a weapon that had a much greater maximum range than a submachinegun was an unpleasant thought. The amassed reserves of ammunition and cost of rearmament was forgotten. The enemy had to be overtaken. Correspondence within the GAU in January of 1944 contained the following note:
"According to tactical-technical requirements set by the Artillery Committee, designers are currently working on two types of weapons for the reduced size round. The first is a heavy submachinegun, the second is a semiautomatic or automatic carbine. Tactical-technical requirements #2463 for a 7.62 mm carbine chambered in the special round defines the following characteristics:

  1. Caliber: 7.62 mm
  2. Muzzle velocity: 750 m/s
  3. Bullet mass: 8 grams
  4. Cartridge mass: 17.3 grams
  5. Maximum pressure: 3200 kg/sq.m
  6. Cartridge length: 56 mm
  7. Propellant mass: 1.6 grams"
Even thought the design was named "model 1943 round", the design of the ammunition and feed mechanisms for new weapons was going poorly. The aforementioned excerpt comes from correspondence discussing its approval. Either way, a small batch of ammunition was produced to obtain ballistic data and perform other trials.

Soviet Garand?

It's not hard to see the difficulty in designing a weapon without the ability to test it. In order to design a weapon around a cartridge that is still in development and whose characteristics are still in flux, a designer needed to have a crystal ball in addition to his pencil and drawing board. Nevertheless, Mikhail Kalashnikov decided to design a carbine for the new cartridge. In his book "Notes of an Arms Designer", he briefly describes this period in his life, mentioning his inspirations:
"This is where I was helped by the American arms designer Garand. I used his method of feeding and automatic extraction of an empty clip, although in a slightly altered way. The charging handle was located in an unusual place, on the left. There were also several other original solutions used."
Most of the section devoted to the carbine recalls how despite a "rather good performance" the carbine was rejected by the chief of small arms purchasing and production, Major General N.N. Dubovitskiy. Kalashnikov recalls that the general was an "impulsive man, but mostly objective and principled. Unfortunately, sometimes his impulsiveness got in the way of evaluation of one design or another. I think that this happened in my case when the general decided to test my carbine personally."

A Garand with an en bloc clip. Kalashnikov decided to borrow this method for his carbine.

Kalashnikov goes on to describe how Dubovitskiy pretended to look for a part that fell out after he shot off one clip, and then spoke out in criticism of the clip mechanism, as well as the charging handle that "ran back and forth in front of my eyes and got in the way". This approach was described by Kalashnikov as "harsh an unfair".

However, documents of the Small Arms and Mortars Scientific Research Proving Grounds (NIPSVO) paint a different picture. For one, the carbine is called "Kalashnikov-Petrov self loading carbine". Unfortunately, no information about the carbine's co-author exists. There are no suitable candidates among the proving grounds designers or officers. Most likely it was an employee of the proving ground, whose input Kalashnikov had reason to credit at the time.

Kalashnikov-Petrov carbine, modern photo.

The name of Major General Dubovitskiy does not appear in either the trials report nor the minutes of the technical meeting that decided the carbine's fate. Of course, this does not mean that it was impossible for a passing general to take part in the trials and give his personal opinion. The testers to remark that an "unexpected ejection of the clip" in front of the shooter's face can "have a negative effect and lower the effectiveness of aimed fire when firing from the carbine". This remark seems quite odd, as the Garand rifle that Kalashnikov borrowed the idea from had already been tested at the same proving grounds, and no issue was recorded with the ejecting clip. The testers at the time wrote that it was more convenient to use the Garand than the domestic SVT-40.

Subjective opinions and objective drawbacks

The report indicates that the Kalashnikov-Petrov Self Loading Carbine (SKKP) had enough issues without Dubovitskiy's comments. According to Kalashnikov's colleagues, there was more in the carbine's design from the Garand than Kalashnikov admits in his memoirs:
"The Kalashnikov-Petrov carbine was based on the Garand self loading rifle, as a result of which there are several assemblies and mechanisms that are analogous to those used in the Garand rifle, for instance the locking of the bolt, feeding, trigger mechanism, and fixing of the receiver."
The report also states that guns with similar locking mechanisms were tested in the 30s and did not give good results. 

Kalashnikov and Petrov also failed to meet the requirements of mass and size. This was a serious omission, especially the former requirement. The GAU sometimes ignored excessive length, especially since there were ways of shortening weapons, as experience showed that the barrel could be shortened a little without a significant result on muzzle velocity. On the other hand, excess weight was not only a serious impediment in the acceptance of a weapon into service, but could result in getting it barred from further development.

The Simonov Self Loading Carbine (SKS), SKKP's more fortunate competitor.

The SKKP was more complicated than its competitor, the SKS. This was especially true for the gas system, trigger mechanism, receiver, and magazine. While the SKKP had one fewer parts than the SKS (105 vs 106), it was much more complicated and difficult to produce.

Another issue was precision. If at 100 meters the results were close to the GAU's requirements, at 300 meters the dispersion was much higher than the military needed.

The carbine also failed reliability trials. The technical requirements indicated that there should be no more than 0.5% misfires in normal conditions. The SKKP gave 0.84% over the span of 11,245 rounds. Most of them were caused by the magazine: jamming during feeding, premature ejection of the clip, jamming of the clip in the magazine, failure to feed. This could have been caused by the aforementioned parallel development of the weapon and ammunition. There was a shortage of model 1943 rounds for experimental work, and Sergeant Kalashnikov was unlikely to be first in line to receive them.

Kalashnikov-Petrov Self Loading Carbine, partial disassembly.

The lifespan of components was also low. Tactical-technical requirements #2941 set the lifespan of a carbine at 12,000 rounds. It was acceptable to have a lifespan of up to three replaceable components of 5000 rounds. Nine parts broke in the SKKP over the span of 12,055 rounds fired, including five that did not survive 5000 rounds.

The performance in difficult conditions trials sealed the carbine's fate, more specifically the trials after soaking the gun in swamp water for 10 minutes. After the carbine was extracted, it did not fire at all, which earned it a grade of "unsatisfactory". This was the end of the carbine. The only question was whether or not Kalashnikov should be allowed to improve his prototype or if it should be declined outright. Interestingly enough, Petrov's name was dropped from the discussion by this point. Perhaps his role in the design of the SKKP was obvious to the proving grounds staff. Most of them were also of the opinion that the SKKP was hopeless. The first to speak, Engineer-Colonel Orlov, said that:
"Improvement of the carbine would require a core reworking of its design, which would essentially involve designing a whole new gun. This kind of development is nonsensical. It is much more reasonable to give the designer a chance to develop a new carbine in accordance with the latest tactical-technical requirements."
As a result, further development of the SKKP was deemed pointless, but the role of this design is hard to overstate. It was here that Kalashnikov first used his locking method, an improved version of which was used on the AK. The failure in difficult firing conditions left a mark on Kalashnikov. He wrote:
"However unfair and cruel this lesson was, I drew my conclusions from it, which allowed me to elevate my work on the assault rifle to a new level of quality."

Original article by Andrei Ulanov. 

1 comment:

  1. It's sad that more of these experimental test rifles di not survive. Be cool to see them featured on Forgotten Weapons.