Russia's Greatest Round: 7.62x39

It doesn't shoot flat, but inside 200 yards the 7.62x39 might be the ultimate battle round.

February 25, 2022 By Joseph von Benedikt

I hear all sorts of rubbish about the 7.62x39 cartridge. “It’s a great deer round,” some proclaim with equal measures of enthusiasm and ignorance. “It hits way harder than the .223 and makes a hole you could push a wheelbarrow through,” others tout. Or, “It shoots flat to 300 yards.” My favorite: “It’s about like the .308.”

Rubbish, rubbish. It’s not a great deer cartridge, it doesn’t shoot flat, and it’s certainly no match for the .308 in terms of accuracy, authority or aerodynamics as distances stretch. But it just might be the ultimate fighting cartridge.

When the 7.62x39 was spawned in the fertile brains of Russia’s People’s Commissariat for Armaments, it was actually a big downsize from the 7.62x54R then in use. The year was 1943, and as the saying goes, new military guns are always designed for the last war. World War II was at full throttle, and a need was perceived for a versatile cartridge suitable for use in light carbines, light machine guns and so forth. The long, accurate bolt-action Mosin-Nagant and its 7.62x54R cartridge, all its virtues notwithstanding, just wasn’t ideal for the fast-paced, close-range fighting common in the bombed-out cities of the Eastern Front.

Russia's Greatest Round — Frontal Area (the area of a cross-section of the bullet) affects how efficiently energy is transferred into the target.

Today’s proponents of the 7.62x39 will often cough and sputter if one suggests that the 7.62x39 is a downsize cartridge and protest that it possesses virtues so far superior to those of the 5.56 cartridge that the two aren’t even in the same universe. But it’s true, and designers understood — indeed, wanted — downsizing. They didn’t want a long-range sniper round or need the power of a traditional bolt-action cartridge; they already had that in the 7.62x54R. They wanted something that worked perfectly through maneuverable, compact semiautomatic and full-auto carbines, provided good on-impact authority inside of 200 yards and was easier to shoot (lower recoil, lower report) than the current service round. Something with the advantages of the Americans’ light, handy .30 M1 Carbine but with better ballistic performance.

An engineering committee was appointed, and engineer NM Elizarov led them to success. It took several years, and WWII was past when the final result of their efforts began rolling off of presses, but the cartridge would go on to become the most popular compact fighting cartridge in the world and see action on every continent.

However, the 7.62x39 is nearing 70 years in age, and most military cartridges that old have either been retired or received dramatic facelifts through new, high-performance projectiles. The 7.62x39 hasn’t. Popularity aside, is it still viable as a battle cartridge?

Keeping in mind its intended sphere (use inside of 200 to 300 yards maximum), let’s look at some accuracy, trajectory and energy figures typical of 7.62x39 ammunition and compare them with other popular fighting cartridges such as the .223/5.56 and .308/7.62x51.

Reliability

With typical Russian focus on practical reliability, particularly with inexpensive component materials such as steel cases, the 7.62 was engineered to take whatever Mother Nature, poorly-trained conscripts and muddy, bloody battlefields could hand out and keep functioning. Undoubtedly, a good portion of the AK47’s reputation for undying reliability is due to the cartridge it shoots, but few people give credit where it is due.

For starters, the 7.62x39 is an ideal length to feed through the magazines and into the chamber of compact, carbine-type semiautos, and the bullet profiles typically used are engineered to flow up feed ramps and into chambers with minimum fuss.

However, the real magic behind the 7.62x39’s reliability is simply its aggressive body taper, which means that until it’s fully seated in the firearm’s chamber, there’s plenty of slop between the body of the cartridge and the steel walls that enclose it. Even more important, when the gun’s extractor gives it a tug, it comes free with minimal resistance — particularly important when shooting high round counts in hot, dirty conditions that cause barrel steel to expand and chamber walls to constrict.

In comparison, NATO’s chosen 5.56 and 7.62 cartridges have little case taper, and when excessive heat, grime, humidity and so forth combine to challenge reliability, they are more prone to malfunctioning (particularly in the hands of a neglectful shooter).

Many great cartridges fight in the hands of military and law enforcement personnel around the globe, but I think it’s safe to say that none surpass — indeed, none can equal — the 7.62x39 in reliability.

While some specialized 7.62x39 projectiles, such as tracer rounds, weigh less or more, the bulk of ammo you’ll find shoots a bullet of 8 grams, or about 123 grains. Early M43-designated ammo was loaded with bullets that featured a mild steel core and a plated steel jacket with lead sandwiched between. Long and stable, these bullets weren’t known for particularly savage wounding ability because they didn’t yaw and tumble easily. They’d usually pencil right through, and unless a vital organ was hit, the wounded would usually heal about as quickly as if they’d been stuck with Aunt Matilda’s favorite knitting needle. Ammunition of the M43 type is still produced in China and elsewhere, but it’s perceived as “armor piercing” and thus banned from importation into the U.S.

Later, around 1960, Yugoslavians designed a shorter bullet without a steel core. Shorter and with the balance shifted rearward, it tumbled far more easily and, as a result, transfered more energy and caused more damage.

Much of the ammunition currently produced, both domestically and abroad, is of softnose expanding design. For fighting purposes, this is good stuff, but few militaries use it in deference to Hague Convention guidelines. (As an interesting aside, the United States is the sole major power that did not ratify the declaration banning the use of “bullets which expand or flatten easily in the human body.”)

Hollowpoint and OTM (open-tip match) ammunition is also commonly available today and typically provides increased on-impact performance.

Most proponents of the 7.62x39 claim that it hits far harder than any .223/5.56 load, and for the most part, they’re right. However, on paper the disparity is less than expected. Let’s compare the 55-grain full metal jacket (FMJ) bullets that were initially used by the U.S. military with typical 123-grain FMJs in the Russian cartridge. A 7.62x39 123-grain bullet at 2,350 feet per second (fps) exits the muzzle with about 1,500 foot-pounds of energy compared with a 5.56 55-grain bullet exiting at 3,250 fps and carrying about 1,300 ft-lbs. That’s only 200 ft-lbs of difference, or about 15 percent.

However, the frontal diameter of the .30-caliber projectile is considerably larger than that of the 5.56. With a total area of .0759 square inch, it’s 93 percent larger than its smaller cousin’s .0394 square inch. That much larger frontal area imparts energy much more efficiently, increasing on-target, in-flesh terminal performance exponentially.

Both of these early FMJ bullets garnered a reputation for zipping right through an enemy soldier without tumbling, leaving a minimal wound. This accentuated the advantage of the 7.62x39’s larger frontal diameter. Later, 7.62x39 projectiles were engineered to perform better acrobatics inside body cavities, but so were .223/5.56 bullets, which closed the gap somewhat.

What about as distances stretch? Keeping within our self-imposed 200-yard distance (what the 7.62x39 was designed for), let’s look at velocity and energy figures. Even Hornady’s 123-grain SST (which is about the most aerodynamic bullet you’re likely to find loaded in a 7.62x39 case) has slowed down to 1,755 fps at 200 yards, at which speed it generates 841 ft-lbs of energy. Early 55-grain FMJ 5.56 bullets slow to about 2,460 fps and produce about 740 ft-lbs. The gap is considerably narrower, but the 7.62x39 still holds the edge. How about the 77-grain match bullets that certain troops use? While they carry little or no more energy at the muzzle, they hold velocity better than the 55-grain FMJs. As a result, they carry about 875 ft-lbs of energy at 200 yards, actually edging out the 123-grain 7.62x39 bullet.

Frontal diameter, however, is a constant, enabling the 7.62x39 to more effectively transfer the energy it does carry no matter the range.

Changing gears, the .308 — or 7.62x51 NATO — is more appropriately compared to Russia’s 7.62x54R, but because AK enthusiasts often tout their chosen cartridge as being in the same realm as the .308, let’s compare the two and dispel that notion. Both have the same nominal frontal diameter (.311 for the Russian .30 caliber and .308 for the American cartridge), so comparing those is moot. What are important are velocity, energy and projectile design.

Traditional 7.62 NATO ammo pushes a 147- to 149-grain FMJ projectile at about 2,730 fps, which produces about 2,500 ft-lbs of energy at the muzzle. That’s 1,000 ft-lbs, or about 66 percent, more than the AK cartridge carries. At 200 yards, it’s 1,740 ft-lbs, more than double the 841 ft-lbs provided by the 7.62x39.

Heavier 175-grain match bullets preferred by snipers carry around 2,640 ft-lbs at the muzzle, increasing the gap to 76 percent more energy. Plus, the long, aerodynamic projectiles hold their velocity far better, making them much more authoritative as distances stretch.

How much better? Substantially at 200 yards, which is within the 7.62x39’s capability. We saw above that the 7.62x39 bullet has slowed down to 1,755 fps, at which speed it generates only 841 ft-lbs of energy. Sierra’s Tipped MatchKing 175-grain bullet in the .308 is still traveling around 2,280 fps and generating more than 2,000 ft-lbs. The difference now is 1,150-plus ft-lbs, or more than 115 percent more impact energy.

No, the 7.62x39 is no sibling to the .308, and let’s leave it at that.

Trajectory Comparison

In practical terms, the 7.62x39 just doesn’t have what it takes to be effective past 300 yards, and that’s stretching it. Muzzle velocity is too low to provide a flat, forgiving trajectory; projectile weight is too low to have the high ballistic coefficient (BC) needed to retain what little velocity it does have; and accuracy with most surplus or bulk-type ammunition isn’t nearly good enough.

Let’s get out of our 200-yard comfort zone for a bit. Just how far out can the 7.62x39 be effective? Using Hornady’s 123-grain SST bullet, which is about as good as the 7.62x39 gets accuracy-wise and ballistic-wise and a superb expanding bullet for self-defense use, let’s examine that question.

As mentioned in the section on terminal ballistics, the 123-grain SST exits the muzzle at about 2,350 fps. When sighted in at 200 yards, the trajectory of the bullet arches 3½ inches high at 100 and drops 14.8 inches low at 300. Just to show how badly it drops off past there, the projectile impacts 45.2 inches low at 400 yards and is an entirely useless 96.6 inches low at 500 yards, at which point it is already going transonic (as a projectile passes through the sound barrier, it is heavily buffeted by vibration, destabilizing it and ruining accuracy).

So, 300 yards is about the maximum practical distance at which a 7.62x39 is effective as a fighting cartridge, and that’s in the hands of a very good rifleman.

Let’s contrast that to the performance of the .223 and .308, starting with a typical 55-grain bullet out of the former. Exiting the muzzle at about 3,200 fps, when sighted in at 200 yards it will impact 1½ inches high at 100 yards, 7.2 inches low at 300, 22.1 inches low at 400 and 47.7 inches low at 500 yards. Accuracy-disturbing transonic velocities aren’t encountered until 750 yards. A good rifleman who knows his sight or scope settings can reliably make precise hits at 500 yards and hit truck-hood-size targets at half again that distance.

How about the Special-Forces-preferred 77-grain cannelured match bullet? It actually starts a little slower and drops a fraction more at 500 yards than the 55-grain FMJ, but it holds on to velocity so well that past there it eats up the difference. It stays supersonic to 850 yards, and in windless conditions top-tier competitive shooters can achieve perfect scores on a 12-inch 10-ring at 600 yards.

Let’s move on to the .308, going straight to the outstanding long-range 175-grain Sierra Tipped MatchKing load at 2,600 fps. Sighted in at 200 yards, it arcs 2.2 inches above the line of sight at 100 yards and drops 8.9 inches at 300. At 400 yards, it’s 25½ inches low, and at 500 yards it’s 51.1 inches low. It stays supersonic to 1,125 yards, enabling consistency to more than 1,000 yards.

Importantly, both the .223/5.56 and .308/7.62 are known for accuracy. A good load in a good rifle will shoot sub-half-MOA with either cartridge, which provides the precision needed to make hits on small targets way out there.

Accuracy-wise, I’ve heard that one of the test parameters of Russian-issue ammunition was that 50 percent of a test group had to land in a 3-inch circle at 300 yards. Hmm. That’s a tough way to quantify accuracy. Where is the other 50 percent expected to land?

Hornady’s SST 7.62x39 load will, in the right rifle, shoot 1-inch groups at 100 yards or very close to that. I’m talking a rifle with a perfect bore, a good trigger and tight, consistent parts. Out of a typical surplus AK assembled with a mash-up of foreign and domestic parts, one is lucky to achieve 3-inch groups at 100 yards.

Taking that a step further, put foreign surplus ammo in a Franken-AK, and you’re lucky to get 6-inch groups at 100 yards. Still, even in this worst-case scenario, that’s easily minute-of-bad-guy out to 200 yards.

Practical Parameters

So, the 7.62x39 falls flat on its face at long range. So what? Inside the 200-yard parameter envisioned by its originators, it offers unsurpassed reliability, adequate accuracy and above-par terminal ballistics. While we didn’t have room to get into recoil levels and sound levels, it’s a relatively friendly cartridge on the shooter’s end, making it easy for new shooters to become fairly proficient with.

In short, as its 70th birthday nears, the 7.62x39 is still at the top of its game. Inside of 200 yards, it may still be the ultimate battle cartridge.