By Rob Kay and RN Price
The 7.62×39 cartridge is perhaps the most popular (and iconic) in the world because of its association with the Kalashnikov assault rifle. It’s a great round within its range envelope, especially effective out to about 200 meters.
Roughly equivalent in energy to the Winchester 30-30, it’s a great pig round and, if you’re over at the Kokohead shooting range, it will really make a steel gong dance — especially when compared to the lighter, though faster-moving 5.56×45/.223 bullet.
Over the years a number of AR manufacturers have taken a stab at building a 7.62×39 AR upper. Earlier incarnations of uppers in this caliber have been fraught with problems.
Reading the forum posts concerning 7.62×39 AR uppers is a study of schizophrenia. Some people have had no problems with their uppers, while others have nothing but misfortune. Two of the most significant issues with the AR15 design running 7.62×39 ammo have been feeding and bolt durability.
Another problem that still comes up from time to time with ARs in 7.62×39 is that of unreliable ignition.
This problem, partially in the lower receiver and partially in the upper, derives from the strength of the spring that propels the AR hammer, the smaller and lighter proportions of the hammer itself, and the degree to which the firing pin will protrude from the bolt face when the hammer drives it forward. If any or all of these parameters are lacking, the notoriously tough primers used by the East European ammunition manufacturers in the 7.62×39 round will fail to ignite, yielding a “click” when the shooter expected a “bang!”
Another potential safety issue brought up in forum posts is the sometimes lack of durability of the bolts supplied with the AR 7.62×39 uppers. The base of the 7.62×39 case is significantly larger in diameter than the base of the traditional 5.56×45/.223 case. It seems as if the structural changes made to the bolt which were necessary to accommodate the larger cartridge base have, in some cases at least, resulted in the bolts for the 7.62×39 variant breaking more often than their 5.56×45 counterparts.
Engineering a magazine that will function properly in an AR (see section below) has also been a challenge with this chambering. Fortunately, AR magazine design for the 7.62×39 round has improved in recent years, and there are some companies out there (such as PWS), that have managed to design a reliable AR upper in 7.62×39.
Find a Headhunter
I would add Headhunters Firearms to the above list.
They are not a big outfit but, they have figured out the 7.62×39 equation. The company was founded by John Nakagawa, a Honolulu native who now lives in Southern California. We ran into him at SHOT last year and were really impressed with his enthusiasm. This year, in addition to the 7.62 upper, he’s built a 458 SOCOM which got some good reviews over at the Industry Day at the Range event which kicks off the beginning of the SHOT show.
A custom builder of AR 15s, Nakagawa started his business making 80% lowers and soon customers asked him to make one-off guns which included cerakoting.
The complete HH762 rifle is built on Headhunters proprietary 7050 billet lower and includes a 16” barrel with an A2 style flash hider, a Magpul ASC carbine stock or a Magpul MOE stock. The upper has the traditional gas impingement design which seems to work just fine.
John will customize your rifle any way you want it with optics or a paint job.
We tested the upper as opposed to the whole rifle.
We really liked what he put together. It’s quite a solid little item with excellent fit and finish. No rough edges or signs of sloppy workmanship. The only thing we didn’t like was that the rail above the receiver had a slightly different spec than the rail over the barrel. We learned that when we placed an ADM QD mount on top for use with a red dot and it was difficult to remove. The cross-bolts got stuck in the slots but fit fine on the rail at the top of the barrel. This was the only mount where we had a problem. All the others we put on (including an ACOG) worked fine.
The good thing about Headhunters is that they stand behind their products so I have no doubt that John will rectify any issues.
We mated the upper with several different lowers and always got a Goldilocks “fit”—not too tight and not too loose. We put hundreds of rounds through the barrel and except for the first ten rounds or so where we had a stove pipe or two (which you might expect during the break-in) it ran flawlessly with both Tula and Silver Bear ammo.
Get the Right Mag
Trying to get the highly tapered Soviet cartridge to feed from a magazine that will work in an AR magazine well has been a big part of the problem in engineering a 7.62 upper. If you look at the constant curve of the Kalashnikov magazine, and compare that to the straight or bent hybrid magazines that were initially available for ARs in 7.62×39, you gotta wonder “what were they thinking?” The AK rounds tended to bind up in the straight parts of the AR magazine, while at the top of the column the next round in line to get stripped out of the magazine by the bolt would often nose-dive into the front of the magazine, or into the base of the chamber of the rifle, causing a failure-to-feed jam.
Suffice it to say, it’s crucial to get a magazine that will properly operate with your Headhunters upper.
ASC manufactures a variety of products from mag racks to a full complement of magazines for semi-auto handguns and rifles. ASC utilizes automatic welding techniques along with an array of high tech heat treating and coating processes that provide dry lubricant and anti-corrosion properties. The result is a dependably feeding mag that gobbled down everything we put in it. (We used both Tula and Silver Bear ammo).
If you read the forums, time and again, users have commented very favorably about ASC and we’ve become fanboys. Headhunters recommends magazines from ASC for their rifles and will provide one with the sale of an upper as well as the complete rifle package.
We tested both their 30 round and 10 round magazines and they functioned perfectly. They are priced at $22 and $17.95 respectively.
For fairness’ sake we also looked at a new generation 28 round mag from C Products Defense it also performed with no hiccups. (Sorry, price not available from the company).
Our staff has a couple of 7.62 uppers between us—including a Colt and a PWS. The HH762 compared very favorably to the PWS which costs about $1200—just the upper. Of course, the PWS is a high-end piston driven system and you’d expect it to be more expensive. That said, the balance, recoil and accuracy of the HH762 was similar enough to the PWS that if you were blind-folded, you’d have a tough time discerning between the two. (We’re not advocating that you shoot blindfolded but we think you get the idea). With blindfolds off, we got about 2” out of the HH762 on our best targets at 100 yds and undoubtedly could have done better with more time and handloads.
Ergonomics on the the handguard were excellent. The bottom of the unit is hemispherical and quite comfortable to hold. On an AR sometimes you feel as if you want a vertical grip but on this upper we didn’t feel that was necessary. The upper is well balanced and easy to point.
Except for the rail “issue” which is an easy fix with a little emery cloth, everything fit perfectly. Not only is the quality of the build excellent, Headhunters will cerakote the rifle to your specs at no extra cost and provide a lifetime guarantee. The complete rifle (with their snazzy billet lower) is $1299.
We were extremely happy with the upper. At $599 it’s really a good deal especially considering the quality you’re getting.
Photos courtesy of On Target staff.
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