AK-47 Bullet Size Quick Summary: > The standard AK-47 bullet size is the 7.62x39mm intermediate cartridge. The bullet itself has a diameter of 7.92mm (0.312 inches), while the casing length is 38.70mm (1.524 inches). The overall length of a fully loaded cartridge is 56.00mm (2.205 inches), typically throwing a bullet weight of 122 to 124 grains.

Specification	Metric Measurement	Imperial Measurement
Bullet Diameter	7.92 mm	0.312 in
Neck Diameter	8.60 mm	0.339 in
Base Diameter	11.35 mm	0.447 in
Case Length	38.70 mm	1.524 in
Overall Length (OAL)	56.00 mm	2.205 in
Standard Bullet Weight	7.90 grams	122-124 grains

Understanding the 7.62x39mm Cartridge Dynamics

The AK-47 was designed around the 7.62x39mm intermediate cartridge, a round engineered to bridge the gap between high-powered battle rifle rounds and submachine gun ammunition. The “7.62” denotes the nominal bullet caliber (roughly .30 caliber or more accurately .311–.312 inches), while the “39” represents the overall casing length of 39 millimeters.

What makes the AK-47 bullet size structurally unique is the aggressive taper of the cartridge case walls. This steep slope allows for incredibly smooth chambering and positive extraction, even when carbon buildup or debris enters the rifle’s receiver. It is a core reason why the AK platform maintains its legendary reliability worldwide.

AK-47 Bullet Variations & Weight Options

While the dimensions of the steel or brass casing remain fixed to fit a standard chamber, the bullets themselves vary based on purpose and load type. Standard commercial and military surplus ammunition typically features a 122-grain or 124-grain Full Metal Jacket (FMJ) projectile.

However, American manufacturers and ammunition suppliers also produce soft point (SP) and hollow point (HP) variants for hunting or defense applications. Because a 7.62x39mm bullet carries a heavier mass than a standard 5.56 NATO round, it delivers excellent kinetic energy transfer at close-to-medium ranges, making it highly effective under 300 yards.

Ballistics and Barrel Twist Rates

To properly stabilize a standard AK-47 bullet size, modern American-made rifles utilize specific barrel rifling configurations. At Riley Defense, our RAK-47 line features precision-machined barrels with a standard 1:10 twist rate. This means the bullet completes one full rotation every 10 inches of barrel travel, perfectly stabilizing the 122gr to 124gr projectiles for consistent accuracy and optimal muzzle velocity.

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Precision Engineered for the 7.62x39mm Round

At Riley Defense, we don’t just understand the geometry of the AK-47 bullet—we build American-made rifles optimized to run it flawlessly. Every RAK-47 variant we manufacture is built to exacting tolerances to ensure reliable feeding, cycling, and extraction round after round.

Explore our classic wood, tactical polymer, and pistol variants to find your next build:

• Browse our full 7.62x39mm AK-47 Lineup
• Check out our 5.45x39mm AK-74 Options