The Kalashnikov assault rifle is a legendary weapon, known throughout the world for its reliability and simplicity. But when it comes to ballistic performance, many owners and enthusiasts wonder: what is the actual speed of a bullet when fired from an AK? This parameter directly affects accuracy, range and stopping power, so understanding it is critical for both sports shooting and professional use.
In this article we will analyze not only theoretical data from technical data sheets, but also practical nuances: how barrel length, cartridge type and even weather conditions can change the initial speed of the bullet. You'll find out why the bullet speed from the AK-74 is 200–300 m/s higher than that of the AK-47, despite the smaller caliber, and how this affects the flight path. And for those who are planning weapon modifications, we will provide comparative tables and expert recommendations.
Technical characteristics: bullet speed in different AK models
Muzzle velocity is the speed at which the projectile leaves the barrel. For Kalashnikov assault rifles, this indicator varies depending on the model and the cartridge used. Let's look at the basic values for the most common options:
- 🔫 AK-47 (7.62×39 mm): initial bullet speed - 710–730 m/s. Classic model with cartridge mod. 1943, known for its killing power at medium ranges.
- 🔫 AKM (7.62×39 mm): thanks to a modernized barrel and a cartridge with a lightweight bullet, the speed increases to 715–740 m/s.
- 🔫 AK-74 (5.45×39 mm): the transition to a small-caliber cartridge made it possible to increase the speed to 900–920 m/s, which improved the flatness of the trajectory.
- 🔫 AK-12 (5.45×39 mm / 7.62×39 mm): depending on the cartridge, the speed is 880–920 m/s (5.45 mm) or 720–750 m/s (7.62 mm).
It is important to understand that the values given are passport details, obtained under ideal conditions (new barrel, standard cartridges, temperature +15°C). In reality, the speed may differ by ±5–10% due to wear and tear of the weapon, quality of ammunition or external factors.
Factors affecting bullet speed
The speed at which a bullet leaves the barrel depends on a set of parameters, among which the key role is played by:
- Barrel length: the longer the barrel, the more time the powder gases take to accelerate the bullet. For example, at AKS-74U (short version) with a 206 mm barrel, the bullet speed is reduced to 730–750 m/s versus 900 m/s for the standard AK-74 (415 mm).
- Cartridge type and bullet weight: A light bullet (for example, 3.4 g in a 5.45x39 mm cartridge) accelerates faster than a heavy one (7.9 g in 7.62x39 mm). However, this results in loss of penetration ability.
- Air temperature and humidity: In cold weather, gunpowder burns more slowly, reducing speed by 1–3%. Humidity also affects air density, increasing resistance.
- Barrel condition: Erosion, contamination or bore deformation can reduce velocity by 5–15% compared to new weapons.
Interesting fact: in mountain conditions (at an altitude of 2000+ m above sea level) the bullet speed increases by 2–5% due to lower air density. This effect is used by snipers to adjust their sights.
Why do shortened AKs lose speed?
When the barrel is shortened, the powder gases do not have time to completely transfer energy to the bullet, since the time of their exposure is reduced. In addition, a short barrel has higher muzzle pressure, which increases muzzle flash and recoil, but does not compensate for the loss of velocity.
Speed comparison: AK vs. foreign analogues
For an objective assessment, let’s consider how the speed characteristics of Kalashnikov assault rifles compare with foreign models. Below is a comparison table:
| Weapon model | Caliber | Initial bullet speed (m/s) | Barrel length (mm) |
|---|---|---|---|
| AK-74 | 5.45×39 mm | 900–920 | 415 |
| M16A4 (USA) | 5.56x45mm NATO | 940–970 | 508 |
| HK G36 (Germany) | 5.56x45mm NATO | 920–950 | 480 |
| AK-47 | 7.62×39 mm | 710–730 | 415 |
| FN FAL (Belgium) | 7.62x51mm NATO | 840–860 | 533 |
From the table it is clear that AK-74 inferior in speed M16A4 and G36 by about 50–70 m/s, but surpasses them in reliability and ease of maintenance. AK-47 it is significantly inferior in speed to modern small-caliber assault rifles, but retains an advantage in the stopping effect of the bullet.
⚠️ Attention: When firing cartridges 7.62×39 mm from a shortened trunk (for example, in AKS-74U with an adapter for 7.62 mm) the bullet speed can drop to 550–600 m/s, which critically reduces the accuracy and range of effective fire.
How to measure bullet speed yourself
If you want to accurately find out the bullet speed from your AK, you can use one of the following methods:
- 📏 Ballistic chronograph: The most accurate device that measures bullet speed using optical or radar sensors. Error - no more 0,5%.
- 🎯 Range test: measure the time it takes a bullet to fly to a target at a known distance (for example, 100 m) and calculate the speed using the formula
v = s / t. The method is approximate, but accessible. - 📱 Mobile applications: some programs (for example, Ballistic Calculator) allow you to estimate the speed along the trajectory, but require the input of additional data (bullet weight, drag coefficient).
When using a chronograph it is important:
☑️ Preparing to measure bullet speed
For amateur purposes, 3–5 shots are enough, with the average value recorded. Scatter more 10% between shots may indicate problems with the weapon or ammunition.
If you don't have a chronograph, go to your nearest shooting range with a ballistics laboratory. Many offer the service of measuring bullet speed for a nominal fee (about 500–1000 rubles).
The influence of bullet speed on ballistics and shooting accuracy
The speed of a bullet directly determines its trajectory, energy and stability in flight. Let's look at the key dependencies:
- Flatness of trajectory: the higher the speed, the flatter (flat) the trajectory will be. For example, a bullet 5.45×39 mm from an AK-74 at a distance of 300 m falls on 30–40 cm lessthan a bullet 7.62×39 mm from AK-47.
- Impact energy: Kinetic energy is calculated by the formula
E = mv²/2, wherev— speed. Even a small increase in speed significantly increases penetration. - Wind influence: High-velocity bullets are less deflected by crosswinds because they spend less time in flight.
However, high speed also has disadvantages:
- ⚠️ Rapid barrel wear: at higher speeds 900 m/s barrel bore erosion accelerates 1.5–2 times.
- ⚠️ Increased returns: especially noticeable in shortened models (for example, AK-105).
For sport shooting, moderate velocity cartridges are often preferred (e.g. 7.62×39 mm with a bullet weighing 8 g), as they provide better accuracy at medium distances.
The optimal bullet speed for an AK depends on the task: for close combat (up to 200 m) 7.62x39 mm is suitable, for long distances (300–500 m) - 5.45x39 mm with a high initial speed.
AK modifications to increase bullet speed
If you are not satisfied with the standard bullet speed, you can consider the following modifications (legal under the laws of your country):
- 🔧 Extended barrel: increase in length by 50–100 mm can add 30–50 m/s to speed. A popular option is a barrel length of 500–550 mm for AK-74.
- 💥 Ammo with enhanced charge: some manufacturers (for example, Barnaul or Tula) release ammunition at increased speed (+5–7% to standard).
- 🌀 Muzzle brakes-compensators: While they don't directly increase speed, they do reduce recoil, which indirectly improves shot accuracy and consistency.
Warning: Any modifications must comply with the laws of your region. In Russia, for example, an independent change in barrel length or caliber requires re-registration of the weapon in Russian National Guard.
⚠️ Attention: Using pressurized cartridges (e.g. 7.62×39 mm "Reinforced") in a standard AK-47 can lead to accelerated wear of the bolt group and even rupture of the cartridge case. Always check the compatibility of ammunition with your model!
FAQ: Frequently asked questions about AK bullet speed
Why is the bullet speed from an AK-74 higher than from an AK-47 if the caliber is smaller?
This is due to the design of the cartridge 5.45×39 mm: it has a more efficient powder charge and a lighter bullet (3.4 g versus 7.9 g for 7.62 mm). In addition, the shape of the 5.45mm bullet is optimized to reduce drag, allowing it to maintain velocity along its trajectory longer.
How does air temperature affect bullet speed?
When the temperature drops to -20°C bullet speed may decrease by 3–5% due to slower combustion of gunpowder. In hot weather (+30°C and above), the speed, on the contrary, increases by 1–2%, but the risk of premature barrel wear increases.
Is it possible to increase the speed of a bullet without changing the barrel?
Yes, but the effect will be limited. Options:
- Using cartridges with a “light” bullet (for example, 3.6 g instead of 3.4 g for 5.45 mm).
- Cleaning and polishing the bore to reduce friction.
- The use of lubricants that reduce resistance (for example, WS2).
However, the speed increase rarely exceeds 1–3%.
What is the bullet speed of the AK-12 compared to the AK-74?
B AK-12 chambered for 5.45×39 mm bullet speed is 880–920 m/s — almost identical to the AK-74. The difference may be due to improved ergonomics and stability of the machine, which indirectly affects accuracy, but not the speed itself.
Why is the speed of an AK bullet often underestimated in games?
In most video games (eg. PUBG or Call of Duty) bullet speed from an AK-47 is indicated in the area 600–650 m/s. This is due to gameplay balancing: the actual speed (710-730 m/s) would make sniper rifles less effective at long ranges.