7.62×39 vs 6.5 Grendel

7.62x39 vs 6.5 Grendel rifle calibers

A side by side comparison of the 7.62×39 versus 6.5 Grendel rounds. Which is a better fit for your next hunting or range trip?

The 7.62x39mm, also known as the 7.62 Soviet or the 7.62 Russian, is one of the most famous cartridges in the world. It’s entirely possible that this is the most-used centerfire cartridge in the world; it’s certainly near the top.

American shooters have started adopting the 7.62x39mm and the partnering AK-style rifle. This highly-effective combination is known for reliability, smooth performance, and excellent ballistics. While originally designed for combat, this cartridge is now being used by Americans for hunting and target shooting too.

But rifle users have plenty of options, and modern cartridges are providing advances in speed, accuracy, and performance. The 6.5 Grendel, for example, is finding its own niche in the sporting-rifle community.

But is 6.5 Grendel a better option than the 7.62 Soviet? To find out, let’s take a close look at these two cartridges.

7.62x396.5 Grendel
Bullet Diameter.311 inches (Variations).264 inches
Rim Diameter.447 inches.44 inches
Case Length1.524 inches1.52 inches
Total Length2.2052.26 inches
Bullet Weight120 - 130 grains (Most 123 or 124)90 to 130 grains

7.62×39 vs 6.5 Grendel: Immediate Differences

Bullet Diameter and Weight

A 7.62x39 vs 6.5 Grendel ammo side by side comparison

The main difference between these two cartridges is the bullet. The cases themselves are fairly similar, with rim and length dimension almost identical. However, the bullet diameter of the 7.62×39 is larger. The Grendel does not have a small bullet, but it’s about 0.05 inches smaller than the 7.62’s bullet.

Ballistic Coefficient Usually Larger for 6.5 Grendel

Ballistic coefficient (BC) is a measurement of a bullet’s ability to resist air drag. Because of the nature of the bullets packed into these cartridges, the 6.5 Grendel usually has a higher BC. This means that the bullet can maintain speeds and trajectory longer, which will come into play when we start examining performance stats.

Cost Likely Lower for 7.62 Soviet

While shopping for ammunition, you’ll likely find that the cost for 7.62x39mm ammunition is cheaper, especially when looking at the lowest-priced rounds. This is largely because the cartridge has been around for over three-quarters of a century and has been adopted by numerous gun owners and organizations across the globe. There are several manufacturers providing budget-friendly, bulk ammo options. With the availability of military surplus cartridges, there are simply more low-cost options for the 7.62.

7.62x39mm vs 6.5 Grendel: Performance

The author shooting 7.62x39 ammo with an AK-47 at a shooting range

To find out how these cartridges really compare, let’s take a look at their performances in velocity, energy, and trajectory.

Muzzle Velocity of 7.62×39 vs 6.5 Grendel

7.62x39mmMuzzle Velocity (fps)300 yrd Velocity (fps)
123-grain Hornady Black SST2,3501,502
123-grain Federal Fusion SP2,3501,593
123-grain Winchester FMJ2,3551,4,63
124-grain TulAmmo SP2,329N/A
6.5 GrendelMuzzle Velocity (fps)300 yrd Velocity (fps)
120-grain Federal Fusion2,6001,881
120 grain Federal American Eagle2,6102,019
123-grain Hornady Black ELD2,5802,090
123-grain FMJ Frontier2,5801,991

Velocity has a major impact on a variety of statistics related to ammunition, including shot trajectory and terminal performance. In this case, we see that the 6.5 Grendel is the faster round. All four of the 7.62 products we examined had muzzle velocities around 2,350. At 300 yards, they also had speeds around 1,500. However, the Grendel was well above 2,500 in all muzzle velocities, and maintained excellent speed at 300 yards and beyond.

Energy Compared

7.62x39mmMuzzle Energy (ft-lbs)300 yrd Energy (ft-lbs)
123-grain Hornady Black SST1,508616
123-grain Federal Fusion SP1,508693
123-grain Winchester FMJ1,515N/A
124-grain TulAmmo SPN/AN/A
6.5 GrendelMuzzle Energy (ft-lbs)300 yrd Energy (ft-lbs)
120-grain Federal Fusion1,801943
120 grain Federal American Eagle1,8151,086
123-grain Hornady Black ELD1,8181,193
123-grain FMJ Frontier1,8181,083

For energies, we see another victory by the 6.5 Grendel. For muzzle energies, most of the 7.62×39 were in the range of 1,500 ft-lbs, while the 6.5 Grendel had performance stats above 1,800. Downrange, the 6.5 Grendel also outperformed the 7.62 Soviet. With velocities right around 1,000 ft-lbs at a distance of 300 yards, it’s clear that this round is capable of delivering knock-down hunting shots at significant distances.

Trajectory / Bullet Drop

Looking through the scope of a 6.5 Grendel rifle downrange

Drop at 400 Yds (200 Yd Zero)
7.62x39 - 123 Gr. Hornady Black45.2 inches
6.5 Grendel - 123 Gr. Hornady Black25 inches
7.62x39 - 123 Gr. Federal Fusion41.6 inches
6.5 Grendel - 120 Gr. Federal Fusion30.5 inches

A good shooter can compensate for dropping trajectories. However, you still want a cartridge that fires as straight as possible. With higher speeds and better ballistic coefficients (in most cases), the 6.5 Grendel appears to be the superior long-range cartridge.

In one comparison shown above, the 7.62x39mm drops over 20 inches more than the 6.5 Grendel. In the other, it only drops 11 inches more, but this is still a significant difference.

Choosing the 7.62x39mm or the 6.5 Grendel

As we mentioned above, rifle choice may guide your decision regardless of performance stats and other factors. However, the one you choose will depend on how you want to use it…

Long-range Precision? Choose the 6.5 Grendel

After reviewing the stats, it’s clear that the 6.5 Grendel is the more desirable cartridge for high-precision, long-distance shooting. You may spend more for every 6.5 Grendel ammo cartridge you buy, but if you want a cartridge that you can zero in and place highly-accurate shots on targets or game animals, this is likely the cartridge for you.

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