In light of recent actions from President Biden and the Department of State, this is unfortunate timing for an article I’ve been meaning to write for a few months. These new sanctions expand the scope of the Obama Administration-era Russian imports ban, focusing on the restriction of ammunition manufactured in Russia. You can read the text here.
Politics and their consequences aside, 7.62×39 is one of my favorite cartridges. I hunt hogs here in Texas almost exclusively using Tula 122 grain HP’s. Up until recently, the round was fun, easy to acquire, and affordable to shoot but that is already changing. Internet experts will often claim 7.62×39 is wildly inaccurate but this doesn’t reflect reality once you step from behind your keyboard and start shooting. While you won’t win any precision matches with it, 7.62×39 is a perfectly accurate round capable of 3-4 MOA in even the cheapest AK pattern rifles. Interestingly, I’ve been able to hold 1 MOA-sized groups using cheap Tula out of a CZ-527 bolt-action.
Why 7.62×39 in an AR-15?
The primary reason to do a 7.62×39 build was it was cheaper to shoot than 5.56. This is no longer true but there are additional benefits. 7.62×39 provides shooters with a lighter platform to launch a .30 caliber bullet from a mil-spec AR. I used to haul an AR-10 on hog-hunts and believe me that got old fast, especially when considering my shots were usually under 300 yards.
Challenges Running 7.62×39 in the AR Platform
You have 2 primary flavors to get 7.62×39 running in an AR or AR-like platform:
- Proprietary ‘hybrid’ AR’s chambered in 7.62×39 such as the CMMG Mutant, PSA’s KS-47, and the LAR-47 from Rock River Arms. These use many milspec AR components but often incorporate a proprietary lower receiver to accept AK magazines. This is a different class of rifle that is outside the scope of this article.
- Building one using a milspec AR lower receiver using specialized magazines designed to accommodate an AR style magazine. This is the type of rifle I will focus on in this article.
Problem 1: Feeding Issues
Building a 7.62×39 AR with a milspec lower involves simply changing the bolt, barrel, and magazine. There are many magazine offerings from ASC, AR Stoner, E-Lander, and others that have seen mixed results in reliably feeding the round.
A cursory search will land you in multiple echo chambers of folks saying this build can’t be done due to the round’s taper responsible for the iconic curve found in AK mags. This taper presents a challenge in AR mags causing consistent feeding issues The cartridge’s geometry just doesn’t play nicely with AR magazine dimensions.
Enter the C-Products Duramag.
The C-Products Duramag 7.62×39 magazine is uniformly considered the best magazine option for your build. They allow for easy insertion into an AR magwell while flaring out to accommodate the round’s taper and feature an improved follower to facilitate consistent feeding. I exclusively use these and have had zero FTF’s in thousands of rounds. Failures to feed represent probably 95% of the challenge in getting this build up and running and these Duramags run like a clock.
Issue 2: Failures to Fire
Steel cased 7.62×39 rounds have notoriously hard primers making it difficult for a standard firing pin to consistently engage the primer. Light primer strikes are another common complaint. Few things are as disheartening as hearing an audible click in the middle of a mag dump.
4 years ago, a common hack to solve for this was to take a Dremel to the neck of your firing pin and remove imprecise amounts of material to allow the firing pin to extend deeper into the primer once the hammer comes into contact with it. This was an inconsistent and probably not the safest approach.
Well, the market provides. You can easily buy an enhanced 7.62×39 firing pin for $7-$10 that provides incrementally more penetration on hard primers.
Nowadays, enhanced firing pins come stock with most 7.62×39 BCG’s. Reputable 7.62×39 BCG’s that I have experience with include AimSurplus, Brownells, and ToolCraft.
Issue 3: Accelerated Bolt Wear
Steel cased ammo is harder on your bolt. In particular, your extractor is prone to wear. Unfortunately, there’s no solution for this. It’s kind of an operational cost. However, when available complete BCG’s from reputable manufacturers typically run $130-$160. You can also pick up spare bolts for $60-$90 and spare extractors. I personally went the route to load up on spare complete BCG’s and bolts.
As far as reliability goes, AimSurplus makes the most well-regarded 7.62×39 BCG but it has rarely been in stock for the last year.
Conclusion
7.62×39 is an impressive round that too often gets written off as being only good for magdumps and plinking. I use it on hogs and whitetail with excellent results and it’s ballistically comparable to 30-30. I love this round chambered in the familiar AR platform because it gives you a bit more power in a lighter package. While it’s been a challenge to get these to function properly, if you have the right components you can easily put one of these together.