Attempts to increase the firepower of an infantryman on the battlefield have been made since time immemorial. From time to time, various compact types of weapons were invented, well made or otherwise. They were often invented not only by professionals, but by people whose duties were far from invention: soldiers, commanders, civilians. The KMB, Baranov's Pocket Mortar, invented by Technician-Lieutenant of the Red Banner Baltic Fleet VVS, G.P. Baranov, belongs to this category.
Before telling the tale of this project, let us step back a little. The lieutenant did not propose something unique. The Germans created and used an analogous design, and a number of hints show that Baranov was inspired by a German sample.
The Germans modernized a flare gun to fire ammunition designed to combat tanks or infantry rather than flares or smoke bombs. The names Sturmpistole, "Assault Pistol", and Kampfpistole Z are widely used. However, there is a mixup. These are common names that were widespread among German infantrymen on the front lines, but not used in official documentation. German historians did not see these names in the archives, but documents use others: Kampfpistole, Leuchtpistole Z, Leuchtpistole. The last one can also mean a regular flare gun.
German LP.34 (Leuchtpistole 34) flare gun.
There is no answer about what kind of weapon should be counted as the"Assault Pistol". It is clear that this category includes weapons with a shoulder stock and a special sight, firing special ammunition. This can be either a regular smoothbore flare gun (Leuchtpistole), a flare gun with a rifled barrel insert (Kampfpistole), or a flare gun with a rifled barrel (Leuchtpistole Z). All three types fired explosive (Sprengpatronen) or armour piercing (Panzergranatpatronen) ammunition. The sight and stock could be installed on all three types or flare gun.
Flare gun with a rifled barrel (Leuchtpistole Z) and a round of ammunition. The inset in the lower left is an angle sight.
The stock was necessary for firing accurately, especially since the powerful recoil was too much to handle with just the hand. However, the sight was not mandatory, you could fire by eyeballing it.
After encountering massed attacks of Soviet infantry backed by T-34 tanks in the winter of 1941-42, the Wehrmacht desperately needed a weapon to combat this phenomenon. It would be some time before the arrival of the Pak 40 and Pak 41, and more expedient measures had to be used. Subcaliber ammunition for the 3.7 cm Pak could be used, as well as a much cheaper solution of converting flare guns into assault pistols.
There is no exact date for the arrival of the assault pistol, but it happened in the spring of 1942. Everything in connection with it was strictly classified. For instance, boxes of ammunition were labelled "Nicht in Feindeshand gelangen lassen — bei Feindgefahr vernichten!", "Do not allow to fall into enemy hands, destroy in case of enemy threat".
Flare gun with a rifled barrel insert (Kampfpistole).
Based on the dates of publication of the list of standard and experimental weapons (Gerätliste D 97/1), we can try to reconstruct the story of the various types of assault pistol. Each edition contained descriptions of all types of weapons used in the Wehrmacht. The close combat weapons section (Nahkampfgerät) lists assault pistol accessories on March 1st, 1942 and a rifled insert on July 1st, 1942.
Most likely, the Leuchtpistole Z flare gun was created first. Visually, the difference was only in a large Z on the breech. Later, certain types of ammunition for the Leuchtpistole Z was used in the regular Leuchtpistole 34, and only then was a rifled insert for the Leuchtpistole 34 invented. This variant was called Kampfpistole. This sequence of events is entirely the author's guess.
Kampfpistole with an extracted rifled insert.
The Germans considered this weapon simple, universal, and effective. It was used not only on the Eastern Front, but also in Africa. Somehow, one of these pistols must have fallen into the hands of Technician-Lieutenant Baranov, and he managed to familiarize himself with it.
Sailor, pilot, and artilleryman in one
Technician-Lieutenant G.P. Baranov was recovering from a wound in the Baltic Front VVS hospital, and he had the spare time to complete and submit his proposal for a pocket mortar. By September, Baranov made his blueprints, completed calculations, produced prototypes, and completed trials which appeared satisfactory to him. On September 24th, he sent all his materials to the Deputy Commander of the Political Section of the Baltic Front VVS, Major-General of Aviation A.N. Filaretov, with a request to allow him to travel to Moscow to meet the Technical Council of the NKV for the approval of his design and the introduction of it into production.
OSP-30 flare gun.
In his accompanying note, Baranov explained that he wanted to create a simple, cheap, and easy to use weapon that required minimal use of materials and highly qualified workers. The proposed weapon was light, compact, and had a range of 200-350 meters (the paper carries a note in pencil about increasing the distance to 600-700 meters). The exploding round would strike a target 2.5-3 meters away. Due to the small size of the ammunition, a large amount could be carried at once, and the sight was easy to master.
The proposal was to arm infantry, scouts, partisans, and pilots with this pistol. Infantry cold use it in street fighting, scouts could confuse the enemy, and partisans could set fire to warehouses and various other objects. Pilots could defend themselves if they went down.
The letter was sent in late September, and in October Major-General Filaretov was appointed the Chief of the Political Section of the Black Sea Front and left the Baltic. Perhaps that is why Baranov's invention was lost. His proposal was only reviewed in March of 1946. It's possible that it was encountered when the navy's papers were being reorganized to deliver to the archive. Baranov served in the navy's air wing, which gave a certain twist to the organizations his letter went through. The weapon was examined from the point of view of naval aviation, for protection of downed pilots. No other application was even considered.
Baranov's pocket mortar.
The invention was not very interesting in 1946. The war was over, there were more effective weapons available, and a proposal from 1943 was no longer timely. Nevertheless, it was examined, and a conclusion was given on March 11th.
"1. This type of weapon is not interesting for naval aviation, as the effectiveness of this weapon against the enemy is less than that of a pistol (TT).
2. The documents pertaining to the KMB mortar are also not interesting for further study, as the calculations were elementary and insufficiently thorough."
How did Baranov aim to create his "pocket mortar"? He noticed that the warehouses and VVS units held a large amount of flare guns, which were, in Baranov's opinion, not useful. The conversion of the OSP-30 could quickly and easily breathe a second life into the "useless" flare gun given a workshop with minimal tools. The OSP-30's handle and firing mechanism were used without changes. A post and a rear sight were soldered or welded to the barrel. An angle sight was added to the left of the handle.
OSP-30 flare gun holster. The KMB holster looked about the same.
The tactical-technical characteristics of Baranov's "pocket mortar" were as follows:
- Mass: 1085 grams
- Overall length: 245 mm
- Caliber: 26 mm
- Mass of one "malyutka" round: 175 grams
- Explosive charge: 8 grams
The converted flare gun was tested with a dummy round. A number of trials showed that if the pistol was not held tightly enough, the recoil of the KMB twisted the hand up and backwards, making it possible to hurt the shooter's arm with the hammer. This forced the installation of a shock absorber that braced against the arm. To soften the blow, it was padded with rubber.
The KMB fired a "malyutka" (baby) round, also developed by Baranov. The projectile was shaped like a droplet and had a stabilizer made from four fins. Three types of rounds were proposed, with different ignition methods for the distance fuse. The fuse used during trials was taken from the ShVAK round. A standard case from a flare gun was used, but it was shortened. 5 grams of gunpowder were loaded into the case, then wadding, then the projectile.
Projectile for Baranov's pocket mortar.
Baranov proposed the use of a leather or imitation leather holster that was very similar to a revolver holster. Pockets for tools and spare parts lined the outside. In general, this was a converted holster from the OSP-30 flare gun.
The ammunition was carried in a special leather or imitation leather bag on a belt. The bag consisted of four sections of five slots each, and could carry a total of 20 rounds. Each section had its own flap. The rounds were inserted with the fuse downward. In order to prevent them from going off from shock, each slot had a shock absorber cap in the bottom that protected the round from impacts or vibration. The flaps had to be precisely aligned to prevent moisture from entering the container. This was very important, since Soviet flares used cardboard casings. The total mass of the ammunition and bag was about 4 kg. Later, Baranov increased the amount of ammunition carried to 30 rounds, and the total weight to 5.2 kg.
During trials, the instant fuse went off when the rounds hit dirt, snow, or any obstacle. The radius of damage was 3.15 meters, and the area covered in shrapnel was about 20 square meters. The range was 250-400 meters. Firing the KMB could be done in any position.
One of the four sections of the ammunition bag.
According to the inventor, the weapon could be used in the role of the 50 mm PM-40 mortar, specifically:
- Destruction of enemy forces in buildings, in attics, or in other cover.
- Instead of hand grenades when destroying machinegun nests, artillery or machinegun crews, and small groups of infantry.
In the end of his proposal, Baranov pointed out that the KMB was simple, allowed fire from up to 400 meters, easy to fire, and quick to come into action. There was enough ammunition carried for one battle, and the round with an instant fuse allows fighting the enemy at point blank range.
The unused weapon is interesting from a technical point of view, especially compared to the German equivalent, which received decent reviews despite all of its drawbacks. Another interesting detail was that Baranov consulted engineers from the Leningrad branch of the TsKB-22 on the use of detonators and distance fuses, managed to independently convert an OSP-30, made an angle sight, produced an tested three types of live and one type of practice ammunition, describe, and document his invention. Considering that the 34 year old inventor was only drafted by the navy in 1941, he likely received a technical education before the war and worked in his field. According to his award orders, Senior Technician-Lieutenant Gennadiy Petrovich Baranov finished the war in the position of a commander of a platoon in a transport company in the 11th Air Base of the Red Banner Baltic Fleet.