Not to be confused with the 7.62x51mm NATO, a totally different cartridge with unique ballistic performance, the 7.62x39mm cartridge, developed in the Soviet Union, is its own animal.
Let’s go over this cartridge, its performance and applications, and why you might want to select a 7.62x39 upper for your next build.
About the Cartridge
Also known as the 7.62 Soviet, the 7.62x39mm cartridge was developed in the Soviet Union in 1943 by the People’s Commissariat for Armaments in response to the need for an effective intermediate cartridge.
It was intended to be used in a wide range of weapons from light infantry rifles and machine guns to select-fire weapons. The result was this cartridge, which has been infamously paired with both SKS and AK-47 rifles. Interestingly, more AK-47 rifles have been built than any other rifle design - making this cartridge one of the most widely used, and most popular, in the world. On top of that, the cartridge has been consistently produced since 1944, giving it an exceptionally long lifespan, too.
The cartridge fires a .30 caliber-class bullet; the originals were 123 grains, but today bullet weights between 125 and 154 grains are common - among heavier ones used in subsonic loads. Here’s what the cartridge offers in terms of performance.
Muzzle Velocity
Naturally, the 7.62x39 will produce muzzle velocity that depends on powder charge and bullet weight (as well as barrel length) but muzzle velocities are usually in the neighborhood of 2,300 and 2,350 FPS. These rounds will generally offer supersonic speeds and performance out to around 500 yards.
There are also subsonic 7.62x39mm rounds. They are loaded with much heavier bullets - often 250 grains or more - and produce far lower muzzle velocities in the area of 1,050 FPS. Some subsonic 7.62x39 ammo also produce a low report and flash signature, making them even more suitable for suppression.
Muzzle Energy
As with muzzle velocity, the muzzle energy produced by 7.62x39 will depend largely on bullet weight and other load data, as well as on barrel length. However, muzzle energies between 1,400 and 1,700 ft-lbs are quite common, and most 7.62x39 loads maintain 1,000 ft-lbs out beyond 100 yards, making them more than suitable for taking medium-sized game like whitetail deer. It’s also interesting to note that these muzzle energy figures are substantially higher than most 5.56 loads, which usually cap out around about 1,200 ft-lbs.
Felt Recoil
For reference, let’s start with the felt recoil produced by 5.56, a viable and competitive alternative to 7.62 Soviet, and one with which it is often compared for ballistic purposes.
By any stretch a light cartridge, 5.56x45mm NATO produces felt recoil scores in the area of 2.5 and 3.5 ft-lbs of felt recoil - very light by any estimation.
The 7.62 Soviet is a little more aggressive - closer to 7 ft-lbs of felt recoil - so a little more than double to close to triple the felt recoil of a 5.56 round.
But, for perspective, consider a 12 gauge shotgun shooting 1 oz slugs, which can produce recoil as high as 20 ft-lbs, almost three times higher than a 7.62 rifle.
Again, this all depends on the weight of the rifle, the weight of the bullet, powder charge, barrel length, and action type, but by any estimation, 7.62 is on the low end of felt recoil.
Trajectory and Effective Range
While most 7.62 Soviet proponents are quick to point out the power and low recoil of the 7.62 Soviet, one of its serious shortcomings is its trajectory, and subsequently, its effective range.
Considering a 7.62x39 round with a 123-grain bullet, in a rifle zeroed at 100 yards, the bullet will drop over 7” at 200 yards and more than 26” at 300 yards.
That’s pretty bad, considering other cartridges like 5.56 are far flatter shooting. On top of that is energy loss. While the same 7.62 cartridge mentioned will maintain more than 1,000 ft-lbs of energy at 100 yards, energy will drop to just about 550 ft-lbs at 300 yards.
This severely limits the maximum effective range of 7.62x39. Some guides will tell you its efficacy as a round should be limited to 400 yards, but most conscientious shooters would keep it well within that range, especially considering bullet drop.
Sectional Density
Sectional density (SD) is a measurement of how effectively a bullet will penetrate a target, and higher is better. For most 7.62x39 rounds, SD is around .182. For a 55-grain 5.56 round, that figure is .157 - but, when you up the mass of the bullet to 68 grains, that figure bumps to .194 - a little better than 7.62.
So on that front, the performance of these two cartridges are very similar.
Ballistic Coefficient
Ballistic coefficient is a metric of how well a projectile is able to overcome air resistance in flight. The higher the ballistic coefficient (BC), the less the bullet will drop and the more it will resist wind drift.
For most 7.62x39mm bullets, the ballistic coefficient is between .15 and .3 - but since we’ve already given figures for trajectory and muzzle energy, you know what you need to know.
Accuracy
The 7.62x39 has gotten a really bad rap as an inaccurate cartridge, but the truth is that most of these stories are anecdotal, and even more likely, that they were influenced by rifles or cartridges that were manufactured to low quality specifications and poorly maintained, if they were maintained at all.
There are definitely better cartridges out there that shoot flatter, but at close ranges (within, say, 200 yards) this is not an inherently inaccurate cartridge. How well you accurize and maintain your rifle will make a much bigger impact on accuracy, anyway.
Availability and Cost
Because 7.62x39mm is and has been so widely produced around the world, and for so long, it is very easy to come by, and very cheap. On the lower end, you can get ammo for as little as 40 cents per round, perhaps even lower if you buy steel-cased 7.62 or buy ammo in bulk. That, like everything else mentioned in this article, makes these cartridges very popular among shooters around the country.
Popular Applications of 7.62 Soviet
As a result of all of the advantages of these cartridges mentioned in this article, there are a wide range of popular applications for the 7.62 Soviet cartridge, including but not limited to the following.
- High-volume target shooting and training
- Plinking
- Competitive shooting
- Defensive applications
- Hunting
Starting with a 7.62x39 Upper Here
All in all, the low cost, wide availability, and solid, reliable performance of this cartridge, especially at close ranges, have kept it popular for nearly 100 years at this point.
If you’re considering building a rifle with a 7.62x39 upper, get it here. We also carry build kits and lower parts kits, along with barrels, charging handles, buffer tubes, and all the other parts you will need to create a functioning rifle.