The term "7.62" refers to a caliber, a unit of measurement for the diameter of a projectile, specifically a bullet. However, it's crucial to understand that "7.62" alone doesn't fully define the cartridge. This number represents the approximate diameter of the bullet in millimeters. Several different cartridges use a 7.62mm bullet, each with unique characteristics. Confusingly, some are also referred to by their NATO designations.
Let's break down some of the most common cartridges using a 7.62mm bullet:
Common 7.62 Cartridges: A Detailed Look
Several significant cartridges utilize a 7.62mm bullet, each with distinct applications and characteristics. Here's a breakdown of some of the most prevalent ones:
7.62x39mm
- Origin: Soviet Union
- Common Uses: Assault rifles (e.g., AK-47, AKM, SKS)
- Characteristics: Relatively short and powerful cartridge, known for its stopping power at close to medium ranges. It's widely used globally due to its widespread adoption and relatively inexpensive production. It's a bottleneck cartridge, meaning the case is narrower at the neck than at the base.
7.62x51mm NATO (.308 Winchester)
- Origin: United States (as .308 Winchester), adopted by NATO
- Common Uses: Sniper rifles (e.g., M14, L1A1), battle rifles, and hunting rifles
- Characteristics: A longer and more powerful cartridge than the 7.62x39mm. It's prized for its accuracy and longer range, making it suitable for precision shooting. It's a full-bodied bottlenecked cartridge. Note the significant overlap with the .308 Winchester. While ballistically very similar, there are minor dimensional differences between the two.
7.62x54mmR
- Origin: Russian Empire
- Common Uses: Bolt-action rifles (e.g., Mosin-Nagant), machine guns
- Characteristics: A powerful, rimmed cartridge known for its long range and stopping power. The "R" denotes that it's a rimmed cartridge.
Why the Confusion?
The confusion arises because the "7.62" only specifies the bullet diameter. The subsequent number indicates the cartridge case length, also in millimeters. This provides essential information for distinguishing between cartridges. Furthermore, some cartridges might be referred to by their caliber and length (e.g., 7.62x39mm) while others utilize different naming conventions, such as the .308 Winchester which is ballistically very similar to the 7.62x51mm.
Understanding Cartridge Specifications
When researching or discussing ammunition, it's vital to know more than just the bullet diameter. Consider these key aspects:
- Bullet diameter: Measured in millimeters (mm) or inches (in).
- Case length: The length of the cartridge casing, usually measured in millimeters (mm).
- Rimmed vs. Rimless: Whether the cartridge case has a rim (7.62x54mmR) or not (7.62x39mm, 7.62x51mm).
- Shape: The shape of the cartridge case can be cylindrical, bottlenecked, or straight walled, influencing the cartridge’s ballistic properties.
By understanding these details, you can accurately identify and distinguish between various 7.62 cartridges and choose the appropriate ammunition for your firearm. Always double-check your firearm's manual to confirm compatible cartridges before use. Incorrect ammunition can lead to serious damage to your weapon and even cause injury.
