The legendary Shpagin submachine gun, known throughout the world as the PPSh, became a symbol of Victory and one of the most popular small arms of the Second World War. When studying its technical characteristics, design or history of creation, the first and most fundamental question that arises among researchers, collectors and military history buffs is the question of ammunition. What caliber is the PPSh?? The answer to this lies in the Soviet designation system and the specifics of the cartridge for which this weapon was created.
The weapon uses a cartridge 7.62×25 mm TT, which is the main pistol cartridge of Soviet and Russian production. These are not just numbers, but a complex engineering system that ensured high penetration and firing range, which distinguished Soviet submachine guns from many Western analogues of that time, which used less powerful ammunition. Understanding the characteristics of this cartridge allows you to better evaluate the tactical capabilities of the weapon in real combat conditions.
In this article we will analyze in detail all aspects of the ammunition supply of the famous machine gun, consider the history of the appearance of the cartridge, its physical properties, and also touch on the topic of alterations and differences from other systems. You will find out why this one caliber was chosen by designer Shpagin and how it influenced the combat effectiveness of the unit.
Historical context for ammunition selection
The choice of ammunition for a new mass-produced submachine gun in the late 1930s was not accidental. By the time the development of the PPSh began, the pistol had already been adopted in the USSR TT (Tula Tokarev), who used the cartridge 7.62×25 mm. The logic of the Red Army command was to maximize the unification of ammunition: a pistol and a submachine gun had to fire the same cartridge. This simplified the logistics of supplying front-line units and allowed soldiers to use magazines from one type of weapon to another in critical situations.
The 7.62×25 mm TT cartridge itself is a development of the German 7.63×25 mm Mauser cartridge, which was widely used in pistols Mauser C96. Soviet engineers modernized the cartridge case and charges, adapting the cartridge to domestic gunpowder and mass production conditions. Unification with its German predecessor, it also played a role later: during the war, captured German 7.63 mm cartridges were often used in Soviet weapons, although with some reduction in performance.
⚠️ Attention: Despite the external similarity and the ability to chamber the 7.63 mm Mauser cartridge into the PPSh chamber, the use of foreign or substandard ammunition in historical weapons can lead to rupture of the cartridge case or damage to the mechanisms. For firing, use only certified cartridges or blanks that meet the original pressure specifications.
Mass production of PPSh began precisely for this caliber, and during the war years millions of weapons were produced that did not know any other ammunition. There were no attempts to change the caliber during the war, since the industry was completely restructured to produce 7.62 mm cartridges, and changing the performance characteristics of the weapon would require the readjustment of all factories, which was impossible in the conditions of 1941-1942.
Technical characteristics of the cartridge 7.62×25 mm
Cartridge 7.62×25 mm TT belongs to the class of powerful pistol cartridges. Its cartridge case is 25 mm long and the bullet diameter is 7.62 mm. The high initial velocity of the bullet is ensured by a large amount of powder charge relative to the caliber, which makes the flight trajectory flatter and the bullet more penetrating compared to common 9 mm cartridges of the time, such as 9x19 mm Parabellum or 9x18 mm PM.
The cartridge's bullet usually has a steel or bimetallic jacket and a lead core. There are various modifications: with a regular bullet, with a bullet with a steel core (for increased penetration), tracer and incendiary options. For the PPSh, which fired in bursts, not only power was important, but also the stability of the supply of cartridges from the magazine, which was ensured by the shape of the cartridge case with a protruding rim.
Below is a table of comparative characteristics of the main PPSh cartridge and its closest “competitors” from the World War II era:
| Characteristics | 7.62×25 mm TT (PPSh) | 9×19 mm Parabellum (MP-40) | 11.43×23 mm (.45 ACP) (Thompson) |
|---|---|---|---|
| Bullet diameter | 7.62 mm | 9.01 mm | 11.43 mm |
| Case length | 25.0 mm | 19.15 mm | 23.0 mm |
| Bullet weight | 5.5 g | 7.5–8.0 g | 14.9 g |
| Initial speed | 400–480 m/s | 350–400 m/s | 250–280 m/s |
| Bullet energy | ~550–600 J | ~500–550 J | ~500–560 J |
As can be seen from the table, 7.62×25 mm has the highest initial speed among the compared samples. This provided the PPSh with an advantage in penetrating ability at medium distances and made it possible to more effectively hit targets protected by light armor or wearing winter clothing. However, the smaller caliber also meant less stopping power compared to heavy .45 ACP bullets.
When studying the characteristics, remember that the actual muzzle energy depends on the length of the barrel. The PPSh with a 269 mm barrel has a higher bullet speed than the TT pistol with its short barrel.
Design features under 7.62 mm
The design of the PPSh was initially designed for a specific cartridge, and all components of the machine gun are optimized specifically for the dimensions of 7.62x25 mm. The bolt group, magazine, magazine neck and extractor are of dimensions that preclude the use of other ammunition without major alteration. A PPSh magazine, especially a disk magazine (“drum”), is a complex mechanical system designed to supply cartridges with certain geometric parameters of the cartridge case and bullet.
Usage blowback in automatics, PPSh requires precise calculation of the mass of the bolt and the force of the return spring for the specific pressure of the powder gases created by the 7.62x25 mm cartridge. If designers had tried to use a more powerful cartridge, it would have required a heavier bolt, which would have made the weapon unusable. Using a weaker cartridge would lead to under-firing of the cartridge and delays in firing.
The PPSh barrel has four right-hand rifling. The rifling pitch is selected to stabilize the light 7.62 mm bullet at high speeds. The barrel was often chrome-plated on the inside to increase service life and facilitate cleaning, which was critically important in conditions of mud and snow pollution on the battlefields.
Why didn't they increase the caliber?
Increasing the caliber would require the creation of a new cartridge, which is impossible in war conditions. In addition, 7.62 mm provided better accuracy and penetration, which was valued above the “stopping effect” in the Soviet doctrine of using PP.
Comparison with teaching staff: is it the same caliber?
Another famous Soviet submachine gun, the PPS (Sudaev Submachine Gun), is often mentioned in the context of the PPSh. The question arises: what is the caliber of the PPS and is it different from the PPSh? The answer is clear: PPS caliber is also 7.62×25 mm. The Soviet command did not change the cartridge system even when switching to more advanced weapon models.
PPS, created later than PPSh (in 1942-1943), inherited the cartridge from its predecessor. This made it possible to use already established cartridge production lines and existing ammunition reserves in the troops. A soldier, transferring from PPSh to PPS, did not need to be retrained in terms of ammunition supply and could use the same boxes of ammunition.
However, there are design differences between stores. If the PPSh was equipped with both disk magazines (for 71 rounds) and sector magazines (for 35 rounds), then the PPS was initially designed only for sector magazines of the new design (for 35 rounds). These magazines are not interchangeable with PPSh magazines, although they use the same cartridge - 7.62×25 TT.
☑️ Comparison of PPSh and PPS
Myths about caliber conversion
Among collectors and reenactors there is often talk about the possibility of converting PPSh to use other cartridges, for example, 9x18 mm PM or 9x19 mm Parabellum. Theoretically, recalibration of any weapon is possible if you have the machine tools and engineering knowledge, but for PPSh this makes no practical sense. Rework would require replacing the barrel, regrinding the bolt, reworking the magazine, and possibly changing the rate of fire.
There were experimental samples and small batches of PPSh converted to the 9x19 mm cartridge for export or captured use, but they are the rarest exceptions. Massive PPSh has always remained a weapon chambered for 7.62 mm. Attempts to use cartridges of other calibers in the original PPSh without modification will only lead to damage to the weapon or an accident.
There is also a myth about the existence of PPSh chambered for 5.45x39 mm (automatic cartridge). This is absolutely false. PPSh is a pistol caliber weapon, and machine gun cartridges have completely different dimensions and pressure. Weapons under 5.45 mm are Kalashnikov assault rifles (AK-74), which appeared decades later.
⚠️ Attention: It is strictly forbidden to attempt to insert a cartridge of a different caliber into a historical weapon. Even if the cartridge is visually similar (for example, 7.62x39 mm or 7.62x54 mm R), its use in a PPSh pistol chamber will result in the cartridge exploding, destroying the weapon and severely injuring the shooter.
Current state of i-cartridges
Today, when the PPSh is mainly a museum exhibit or a collectible, the question “what caliber is the PPSh” is relevant for manufacturers of souvenir and cooled weapons (SHP). Factories producing copies of PPSh for reenactors strictly adhere to the original caliber 7.62×25 mmusing special blank cartridges.
The production of 7.62x25 mm live ammunition in Russia and the CIS countries continues to this day, although in smaller volumes, for special services and export. The cartridge turned out to be so successful that it outlived its era and is still in service in some countries. For owners of cooled PPSh, special primed cartridges are produced that imitate the sound and flash of the original shot.
When purchasing cartridges for reconstruction, it is important to pay attention to the markings. Original WWII cartridges may be of collector's value and should not be used for shooting due to possible degradation of gunpowder and corrosion of the cartridge case. Modern industry offers high-quality options that are completely safe for use in cold weapons.
The main result: the PPSh was created, fought and remained in history exclusively as a weapon chambered for the 7.62x25 mm TT cartridge. Any other calibers are either myths or the result of an artisanal alteration that has nothing to do with the original design.
Frequently asked questions (FAQ)
Is it possible to shoot PPSh with German 7.63 mm cartridges?
Technically, the 7.63x25mm Mauser cartridge has very similar dimensions and can be loaded into PPSh. However, the pressure in the German cartridge may be different, and the cartridge case does not have a ledge, like the Soviet 7.62x25 TT. This may cause extraction problems or damage to the weapon. In emergency wartime conditions this practice was allowed, but for modern use it is not recommended.
Why is the caliber 7.62, and not 9 mm, like the Germans?
The Soviet school of gunsmiths relied on penetrating power and flat trajectory, which was ensured by 7.62x25 mm. The German 9x19 mm has a greater stopping effect, but less penetration. In addition, the transition to 9 mm would require a complete change in the cartridge base, since the main pistol cartridge in the USSR was precisely the 7.62 TT.
How many rounds did a standard PPSh magazine hold?
The PPSh was equipped with two types of magazines: a RPSh disk magazine with a capacity of 71 rounds and a sector magazine with a capacity of 35 rounds. The disk magazine was heavy and difficult to load, so by the middle of the war they began to abandon it in favor of lighter and more reliable sector magazines.
Is the 7.62×25 cartridge for PPSh currently being produced?
Yes, the 7.62×25 TT cartridge is produced in Russia (for example, by the Barnaul plant) and other countries of the post-Soviet space. It is used for firing TT pistols, Stechkin Pistol (APS) and submachine guns. Cold and traumatic versions of this cartridge are also produced.