5.56mm vs 7.62x39mm
Ballistics Performance Comparison of 5.56mm vs 7.62x39mm Cartridges
The 5.56mm NATO and the 7.62x39mm Soviet were both developed as military cartridges in the 1960s, and have remained in the public eye ever since. The greater energy and heavier bullets of the 7.62x39mm allow it to bring down larger game, while the higher velocity and lighter recoil of the 5.56mm might make it preferable for shooters targeting smaller game. Since both have inexpensive ammunition and are popular on semi-automatic platforms such as the AR-15 and the AK-47, they are popular cartridges, and the debate between them is perhaps just as popular.
The following ballistics tables show a side by side comparison of the 5.56mm vs 7.62x39mm based on bullet weight and performance metrics including velocity, energy, usage and recoil.
| 5.56mm NATO | 7.62 x 39MM | ||
|---|---|---|---|
| Bullet Velocity (Muzzle) | 3,060 ft/s | 2,350 ft/s | |
| Bullet Velocity @ 100 yds | 2,714 ft/s | 2,053 ft/s | |
| Bullet Velocity @ 200 yds | 2,394 ft/s | 1,780 ft/s | |
| Bullet Velocity @ 300 yds | 2,095 ft/s | 1,535 ft/s | |
| Bullet Velocity @ 400 yds | 1,820 ft/s | 1,324 ft/s | |
| Bullet Velocity @ 500 yds | 1,571 ft/s | 1,159 ft/s | |
| Bullet Energy (Muzzle) | 1,289 ft⋅lb | 1,508 ft⋅lb | |
| Bullet Energy @ 100 yds | 1,014 ft⋅lb | 1,151 ft⋅lb | |
| Bullet Energy @ 200 yds | 789 ft⋅lb | 865 ft⋅lb | |
| Bullet Energy @ 300 yds | 604 ft⋅lb | 643 ft⋅lb | |
| Bullet Energy @ 400 yds | 456 ft⋅lb | 479 ft⋅lb | |
| Bullet Energy @ 500 yds | 340 ft⋅lb | 367 ft⋅lb | |
| Hunting Usage @ 0 yds | Medium Game | Large Game | |
| Hunting Usage @ 100 yds | Medium Game | Medium Game | |
| Hunting Usage @ 200 yds | Small Game | Small Game | |
| Hunting Usage @ 300 yds | Small Game | Small Game | |
| Hunting Usage @ 400 yds | Small Game | Small Game | |
| Hunting Usage @ 500 yds | Small Game | Small Game | |
| *Cartridge ballistics, usage and recoil figures taken from Sportsman's Warehouse rifle ballistics and rifle recoil tables. Recoil score based on weighted average of recoil energy and recoil velocity normalized between 1 and 10. | |||
Velocity
The high velocity is one of the main attractions of the smaller 5.56mm NATO. Note that a smaller bullet will always travel faster than a heavier model of that same bullet at the same powder load, and we are comparing a 62 grain 5.56mm NATO against a 123 grain 7.62x39mm. Out of the muzzle, the 5.56 is traveling a full 710 ft/s faster than the 7.62x39mm. At 300 yards, this advantage has decreased slightly to 560 ft/s faster for the 5.56 NATO. At 500 yards, the 5.56mm is traveling 412 ft/s faster, still an impressive lead even as it loses its power a bit faster than the 7.62x39mm.
Energy
While a lighter bullet is a benefit for velocity, a heavier bullet brings more energy and more stopping power. Here, the 7.62x39mm takes the advantage. Out of the muzzle, the 7.62x39mm has an extra 219 ft-lbs over the 5.56mm. At 300 yards, this difference has narrowed to 39 ft-lbs. At 500 yards, the 7.62x39mm has just 27 ft-lbs more energy than the 5.56mm NATO.
Trajectory
Along with their higher velocity, the 5.56mm also have a flatter trajectory, as the lighter bullets are less impacted by gravity. Let’s compare a 77 grain 5.56mm against a 123 grain 7.62x39mm, both zeroed at 200 yards. At 300 yards, the 5.56mm will drop 8.6”, compared to 14.8” from the 7.62x39mm. At 400 yards, the 5.56mm will drop 25.6” compared to 45.2” from the 7.62x39mm. At 500 yards, the 5.56mm continues its advantage, dropping 53.5” compared to 96.6”.
Wind drift measures how much a bullet will move in the face of a 10mph crosswind. Comparing a 70 grain 5.56mm against a 123 grain 7.62x39mm, the 5.56mm again has a straighter shot. At 200 yards, the 5.56mm will drift 4.3” against 6.2” from the 7.62x39mm. At 400 yards, the 5.56mm drifts 19.3” compared to 27.9”; and at 500 yards, the 5.56mm drifts 32.1” against the 7.62x39mm’s 46.2”.
Recoil
Both of these cartridges are seen as mild recoiling. However, the 5.56mm NATO has an even milder recoil than the 7.62x39mm Soviet, classifying it as an extremely mild recoil. If you’ll be shooting many shots in a day (as many semi-automatic owners intend to do), this recoil can certainly make a difference on your shoulder. In addition, recoil impacts your ability to shoot the rifle accurately. However, most shooters should be able to handle the recoil of either of these calibers after some training.
Versatility
The extra power and heavier bullets of the 7.62x39mm make it appropriate for larger game at longer distances than the 5.56mm NATO. It is still not a big game cartridge by any means, but medium game at short distances can be taken with it. The 5.56mm is more suitable for pest control and small game with thin skins. Thanks to the light recoil and the prevalence of both cartridges on semi-automatic platforms, they are good choices for hunters who will need to fire a large number of shots, such as varmint hunting or feral hog hunting.
Price & Availability
The 5.56mm NATO and the 7.62x39mm Soviet are both extremely popular cartridges, especially with those using semi-automatic platforms. Variations are therefore offered from many of the major ammunition manufacturers, and it’s unlikely that you will be unable to find ammunition in either caliber. These are also both inexpensive calibers, and since they also shoot mildly, they are good choices for plinking and target practice. Note that some cheap surplus military ammunition can have worse accuracy than other types of ammunition, which has earned the 7.62x39mm in particular a poor reputation for accuracy. If you’ll be hunting, an accurate round is of the utmost importance.
Size Comparison
The 5.56mm NATO and the 7.62x39mm Soviet are fairly comparable in size. The 5.56mm has a smaller bullet diameter of .224”, compared to the .310” of the 7.62x39mm; and a smaller rim diameter, of .378” compared to .447”. However, the 5.56mm also has a longer case length of 1.76” compared to 1.528”. The overall lengths are very close, with the 5.56mm at 2.26” and the 7.62x39mm at 2.2”. The 7.62x39mm offers heavier bullets ranging from 120-125, while the 5.56mm NATO bullets typically come in the range of 55-77.
Rifle Type
Most shooters who are interested in the 5.56 NATO or the 7.62x39mm have chosen them thanks to their proliferation on semi-automatic and AKM platforms. The 5.56 NATO is particularly popular on AR platforms, while the 7.62x39mm is a mainstay of the AK-47. You may find some AR platforms chambered in 7.62x39mm, but it’s certainly not as common. Both calibers can also be found chambered in some bolt-action rifles.
Which Caliber is Best?
The 5.56mm NATO shoots light, fast bullets that are more aerodynamic, flatter shooting, and higher speed than the 7.62x39mm. However, the extra weight and energy of the 7.62x39mm might be just what you need if you want to take out even medium-sized game. If you’re not concerned about hunting, your choice between these calibers might really be a choice between the AR-15 and the AK-47. Ultimately, these are different cartridges for different purposes, though both have military roots and are popular on semi-automatic platforms. Your purposes with the caliber will determine which is most appropriate for you.
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