Caliber of the Kalashnikov assault rifle: 7.62 or 5.45?

The question of which caliber The Kalashnikov has a legendary assault rifle, which often causes controversy among small arms lovers and novice collectors. Many people mistakenly believe that there is a single standard, although the history of Soviet and Russian weapons shows a clear evolution of ammunition. Understanding the difference between the main types of cartridges is essential for the right choice of weapons, whether for service, sport or for the purpose of the weapon.

The main difference lies in the diameter of the bullet and the energy of powder gases, which directly affects the penetration ability and accuracy of the battle. The classic version, known throughout the world as AK-47It uses an intermediate power cartridge that provides a high stopping force. More modern modifications have switched to a low-pulse cartridge, which allowed to improve the controllability of the machine when firing bursts.

In this article, we will discuss in detail the technical characteristics of both main calibers, their advantages and disadvantages in various operating conditions. You will learn why the military has switched to a smaller caliber and in what situations the good old "seven sixty-two" remains the uncontested leader. This knowledge will help you not to get confused in the variety of modifications presented in the market of civilian and service weapons.

Historical context and appearance of 7.62 mm

The history of the creation of the Kalashnikov assault rifle is inextricably linked with the development of a new ammunition, which was to replace rifle cartridges and pistol cartridges in the intermediate niche. In the postwar years, the designers were tasked with creating weapons that are effective at distances up to 400 meters, but at the same time compact and light. It was then that the cartridge of the 1943 model was adopted, which became the standard for the first mass-produced automatic rifle.

caliber 7.62 mm 7.62×39 mm became a symbol of the era and the main ammunition of the armies of the Warsaw Pact countries. The bullet’s high energy allowed it to confidently break through brick walls, wooden barriers and standard helmets of the time. The weapons under this cartridge, including AKM and early versions AKAIt is highly reliable even in extreme pollution conditions.

However, this caliber had its limitations, which became noticeable with the development of individual armor protection. The bullet had a relatively low initial speed compared to more modern counterparts, resulting in a steeper flight path. The shooter had to make large adjustments when shooting at extreme distances, which reduced the likelihood of hitting the target with the first shot.

⚠️ Note: When buying civilian weapons (Saika or Boar type carabins) under the cartridge 7.62x39, be sure to check the availability of the appropriate license category "O" (smoothbore) or "A" (ribbed), as legal norms may change.

For a long time, this caliber was considered the standard for assault rifles around the world. Its production was established in dozens of countries, and the technology of cartridge production became one of the most widespread in history. Even today, many special forces prefer weapons for this ammunition for its penetration power.

Transition to a low-pulse cartridge 5.45 mm

In the late 1960s, a new arms race began in the global arms industry, triggered by the successes of the Americans in Vietnam with their M16 rifle. Soviet engineers responded with the creation of a low-pulse cartridge caliber 5.45 mm (5.45x39 mm), which was adopted with the machine gun AK-74. This decision has radically changed the ballistic characteristics of small arms.

The main advantage of the new caliber was a significantly higher initial bullet speed, reaching 900 m / s and above. This made the trajectory of the bullet more flat, simplifying the aiming at medium and long distances. In addition, the reduction of caliber allowed to reduce the weight of the soldier’s wearable ammunition, which is critical in the conditions of protracted hostilities.

The reduction in the mass of the mobile parts of the machine under a new cartridge had a positive effect on the accuracy of shooting, especially when firing in bursts. The recoil became softer and more predictable, allowing even less trained fighters to hit targets more effectively. The design of the store has also undergone changes, getting a characteristic bending and plastic cheeks for ease of wearing.

• 🎯 The high initial velocity of the bullet provides a flat trajectory.
• ⚖️ Reducing the weight of ammunition allows the soldier to carry more ammunition.
• 🔫 Reduced recoil increases the accuracy of firing bursts.
• 🛡️ Special bullets (BZ, T) effectively penetrate body armor.

The transition to 5.45 mm was not instantaneous, and for a long time the two calibers coexisted in parallel. By the 1980s, however, the new standard had completely ousted its predecessor from the Soviet army’s main arsenal. Today, this caliber remains the main one for the Armed Forces of the Russian Federation and many other countries of the post-Soviet space.

Comparative ballistics and penetrating ability

When choosing between the two main Kalashnikov calibers, ballistics is often a key factor. The 7.62x39 mm cartridge has a larger bullet mass, which gives it an advantage in transmitting energy when hitting soft tissues or unprotected targets. However, a 5.45 mm bullet, due to its high speed and design (often with a shifted center of gravity or steel core), behaves differently when faced with an obstacle.

The penetration capacity of the caliber of 5.45 mm is higher in relation to modern armor protection. The steel core, which occupies most of the bullet’s volume, allows it to pass through the bulletproof vests of the protection class, which will hold the bullet 7.62 mm. This was a decisive argument in favor of switching to a low-pulse cartridge in the regular army.

The table below compares the main characteristics of both munitions for clarity:

Despite its lower mass, the 5.45mm bullet has a huge destructive potential inside biological objects due to the effect of tumbles after encountering a dense environment. This makes it extremely dangerous, despite the visual "smallness" compared to the "classic".

Influence of caliber on the design of the machine

The change in caliber required not only the replacement of the barrel, but also a serious reworking of the entire automatic weapons. Gas exhaust system of the machine AK-74 It was reconfigured to lower pressure of powder gases, which required a change in the diameter of the gas chamber. This ensured the reliable functioning of the mechanisms without excessively increasing the speed of movement of the shutter frame.

The trunks of the 5.45 mm machine guns received a new cut with a step of 195 mm (vs. 240 mm at 7.62 mm), which is necessary to stabilize a lighter and longer bullet in flight. Also changed the shape of the muzzle brake-compensator, which became two-chambered and more effective, extinguishing the toss of the barrel when fired.

Stores for low-pulse cartridge were made of aluminum alloy with plastic linings (bakelite), and later - entirely from plastic. This allowed to reduce the weight of the equipped store and increase its corrosion resistance. The shape of the store became more pronounced, with a characteristic "beak", which sometimes made it difficult to wear in some types of unloading systems designed for direct stores.

⚠️ Warning: Installation of a barrel or gas exhaust system from 5.45 mm on a 7.62 mm receiver (and vice versa) is impossible without a serious alteration of the weapon and can lead to rupture of the cartridge when fired.

The ergonomics of weapons have also undergone changes. The butts of the 5.45mm assault rifles were lighter, often foldable (metal or plastic), which improved the mobility of paratroopers and armored personnel. The balance of the weapon shifted, making the machine more "spinning" in the hands.

Civilian turnover and hunting carbines

In the civil market of Russia and CIS countries, both calibers are widely represented, but in different niches. The 7.62x39 mm cartridge is the most popular for hunting medium game. Carbines of the Saiga, Boar and Hammer type under this caliber allow to extract boars, roe deer and bears, providing the necessary energy of the shot.

The low-pulse cartridge 5.45 mm in civilian circulation is often found in the form of a 5.45×39 cartridge, but there is also a commercial version of it - 5.56×45 (NATO), although this is another topic. Hunters use 5.45 mm less often, mainly for shooting small game or for entertaining shooting (plinking) because of the cheapness of ammunition.

The cost of ammunition plays an important role for owners of civilian weapons. The 7.62x39 ammo is generally cheaper and more affordable in regions where the hunting population is large. 5.45mm ammunition is more often purchased by high-speed shooting athletes (IPSCs).

• 🦌 For hunting ungulates, a caliber of 7.62 mm is preferable.
• 🎯 For sports shooting and training, 5.45 mm are often chosen.
• 💰 The budget option for frequent shooting is a 7.62 bimetallic bullet.
• 🏠 To protect the house near settlements 5.45 safer (less ricochets).

Gun owners should carefully monitor the marking of ammunition so as not to break the law accidentally.

Modern trends and multicaliber

The modern development of small arms is on the path of modularity. New samples, such as AK-12 and AK-15, are created taking into account the possibility of rapid change of caliber or unification of nodes. The AK-15, for example, returns to the 7.62x39 mm caliber, but on a new element base, combining the power of the old cartridge with ergonomics and attachments of modern times.

Special units often use weapons under the cartridge 7.62x39 mm for work in urban and indoor environments, where guaranteed penetration of light shelters and doors is important. At the same time, for actions in open spaces and mountains, priority is given to the trajectory of 5.45 mm.

A unique feature of modern Russian developments is the creation of a 6x49 mm cartridge for promising complexes, but the classic 7.62 and 5.45 calibers remain uncontested for mass armament for many years. This ensures logistical compatibility and simplifies the supply of troops.

The technology of cartridge production is also being improved. New types of gunpowder appear, the quality of bimetallic shells improves, coatings are introduced that reduce the wear of the barrel. All this allows you to keep the relevance of calibres developed decades ago.

FAQ: Frequently Asked Questions