The modern tinkerer has as many options at his or her disposal as the imagination will allow, especially when it comes to building AR-style rifles.
While the vast majority may still be cobbled together with parts spec’d out for 5.56/.223 and 7.62x51mm cartridges, there is a dizzying degree of variety in parts available for rifles chambered in .50 Beowulf, .300 BLK, .22 Nosler, and many, many others.
One of these cartridges is the old 7.62x39mm Soviet cartridge, first developed in 1945 at the end of World War II. Due to the former Soviet Union’s massive sphere of influence, this cartridge has been widely proliferated and spread around the world.
It even saturated the U.S. market at the end of the Cold War when surplus, ex-Soviet rifles, and ammo flooded our market at low prices
For a while, it seemed like no shortage would ever come, and though times are changing once more, and new embargoes are being levied, 7.62x39mm ammo remains, for the time, fairly cheap.
So are parts for 7.62x39mm rifles. So, what are the reasons you might want to choose a 7.62x39 upper for your next build?
Let’s just take a look at the more obvious.
Hunting Practicality
There are absolutely better hunting cartridges out there than the 7.62x39 Soviet. We’re not trying to say otherwise. But if this is a shoot-out (pun intended) between 5.56 and 7.62x39, there are definitely some advantages to the latter.
Take, for instance, a 62-grain 5.56 bullet (muzzle velocity 3,060 FPS) vs. a 123-grain 7.62x39 bullet (muzzle velocity 2,350 FPS).
Muzzle velocity does not tell the whole story. We need also to look at muzzle energy and then trajectory.
That 5.56 round is going to produce about 1,289 ft-lbs of energy at the muzzle, compared to the 7.62’s 1,580. At 200 yards, the 5.56’s energy will drop by nearly 40%, down to just less than 800 ft-lbs. The 7.62’s will remain at about 865.
It maintains its stopping power for longer, but there is a catch. It has quite a badly drooping trajectory. A 5.56 bullet will drop around 3” at 200 yards, and a 7.62x39 will drop about 6. This trend continues with the 7.62 dropping about twice as fast or faster than the 5.56.
But, at close and intermediate ranges, the 7.62x39 produces much more stopping power, which makes it superior on medium and large game, at those respective distances.
Now, with all of that said, let’s keep some other things in mind. The low cost and wide availability, not to mention low recoil of 5.56, make it for many the preferred cartridge for most varmint applications and other small to medium game like coyotes and foxes.
But for anything bigger, at close to intermediate ranges, the 7.62x39mm Soviet is just a better choice with greater stopping power.
Defensive Applications
No matter how you slice it, the 7.52x39 is loaded with a bigger, heavier bullet than a 5.56x45mm NATO round, period.
That creates a larger permanent wound channel and, as has already been demonstrated, higher stopped power, especially at close and medium ranges.
The basic ballistics have already been examined. It is clear that at the right ranges, the 7.62 has greater power. The only drawbacks are that it produces slightly more recoil and potentially too much penetration. That said, the greater recoil is truly minimal, and a muzzle brake or heavier buffer tube weight can more than make up for that.
For defensive applications, and with an appropriate bullet (soft-tip or hollow point) this gives the 7.62x39mm the edge in some defensive applications.
It should be said, however, that there can be a risk of overpenetration with this larger, more powerful cartridge - but still, stopping potential remains higher.
Availability/Cost of Parts
This we must offer as a caveat because of some changes that have currently come about in the market, but one of the things that has historically (in the last thirty years, at least) made 7.62x39mm so popular as a cartridge has been the unbelievable availability of the cartridge, at ridiculously low prices.
Since the Soviet Union collapsed, Russian producers have sent a lot of cheap, steel-cased 7.62 our way - like TulAmmo, for instance. This has created a big demand for the cartridge as well as rifles that shot it, like the AK and SKS.
Most of the early problems that plagued 7.62x39-chambered AR-style rifles (like unreliable magazines and low-quality bolt carrier groups) are in the past, and for the time being, it’s still a cheap and pretty widely available cartridge.
A Word to the Wise
One legitimate concern that you might have with the prospect of building an AR with a 7.62x39 upper is the continued availability of parts and ammo.
As for parts, we produce plenty, like assembled uppers with bolt carrier groups, complete build kits, and parts for AR pistols.
But as for the ammo, that’s another story. At the end of 2021, the United States levied an embargo on imports of ammunition from Russia, which produces a large quantity of the world’s 7.62x39mm ammo. It is their cartridge, after all.
Other producers like Norma still make it, but most steel-cased, cheap 7.62 still is made in Russia. Once our current domestic stockpiles run out, we won’t have anywhere to get it cheap. Worst, current facilities can’t be easily re-tooled to load steel cases. There’s just too much of an operational difference between producing brass and steel ammo - even of the same casing.
So, be prepared for that.
Looking for an Alternative? Go with a .300 Blackout Upper
One more word of wisdom. If you like the performance of the 7.62x39mm but are looking for something that will continue to be available even when 7.62 ammo and parts dwindle, consider building an AR with a .300 Blackout upper instead.
The 3.00 BLK, based on the 5.56, is able to use the AR’s standard bolt carrier group; only a different upper is needed, and can even feed from some 5.56 mags, too. Moreover, it offers greater stopping power at close to intermediate ranges, just like 7.62x39mm.
On top of that, we produce plenty of our own ammo domestically, and some 5.56 casings can be trimmed and widened before loading .300 BLK, so even if there is a shortage, you may be able to reload your own.
That is one option for you if the current trade situation regarding 7.62x39mm looks less than positive but you want something with roughly similar ballistic capabilities.
Looking for 7.62x39 Uppers and Parts?
Looking for complete uppers, and 7.62x39mm uppers for your next build? We carry a wide range of upper assemblies, complete with gas blocks, charging handles, and bolt carrier groups - everything you need for your next build.
If you’re looking for a complete 7.62x39 upper receiver, take a look through our collection and then contact us at Sales@MCSGearup.com if you have any questions. In addition to 7.62x39 complete upper builds, we also carry everything else you need for an AR chambered in 7.62x39mm, including lower parts kits, handguards, muzzle devices like flash hiders, and more.