January 04, 2011
How to up the performance of 7.62x39 ammunition on the cheap.
By pulling the bullets from inexpensive ball ammo and replacing them with a suitable expanding bullet, you can improve the 7.62x39's accuracy and terminal performance.
After coming into its own in the horror that was the Eastern Front, the intermediate cartridge concept has slowly fallen out of favor. Although Germany, with its 7.92x33 Kurz, is often considered the originator of this cartridge type, such is not the case. The concept for a true intermediate cartridge was actually conceived in Imperial Russia by weapons designer Vladimir Grigoryevich Fedorov.
Prior to the First World War, Fedorov developed a rimless 6.5mm cartridge driving a 131-grain projectile at 2,821 fps. However, due to resistance from the czar, Fedorov had to make due with the readily available 6.5x50 Arisaka cartridge.
The next Russian attempt at fielding an intermediate cartridge was much more successful. The 7.62x39 M43 cartridge was adopted in 1943 and remained the Soviet standard until replaced by the 5.45x39 M74 cartridge in 1974.
Driving a 123-grain FMJ-BT projectile with a mild steel core at approximately 2,330 fps, it has proven fairly effective. Its strong points include reduced bulk and weight compared to a full-size rifle cartridge, reduced recoil, fairly good penetration through intermediate barriers, low manufacturing costs and sufficient terminal performance at common engagement ranges.
While the 7.62x39 cartridge does many things well, it does nothing outstanding. It is considerably heavier than more modern military cartridges such as the 5.56x45 NATO, 5.45x39 M74 and 5.8x42 Chinese. It has a trajectory similar to a thrown bowling ball. Its recoil is noticeably heavier than modern small bore military cartridges, and "accuracy" and "7.62x39" have never been synonymous. Last, terminal performance of standard M43 steel-core ball has always been lackluster.
For American shooters this cartridge's main attraction has always been its inexpensive price. There was a time when you could purchase 1,000 rounds of 7.62x39 ball for $70.
Unfortunately those days are long gone. Like all other ammunition, the price of 7.62x39 ball has steadily climbed. Today it's often more than $200 per 1,000 rounds.
Despite the spike in prices, the 7.62x39 cartridge remains hugely popular among American shooters. However, those who would like to utilize this intermediate cartridge for self-protection face a lack of modern loads in this caliber. Due to the availability of inexpensive foreign ammunition, domestic manufacturers have largely ignored this round.
To be blunt, AK shooters tend to be the cheapest shooters on the planet. In years past they were interested only in the best deal they could find while leafing through the pages of Shotgun News. So designing a modern dedicated projectile, and developing a suitable load, for this cartridge was not economically viable.
However, the introduction of the 6.8x43 SPC and 6.5x38 Grendel cartridges stirred interest among many shooters for a modern 7.62x39 load. Both of these modern intermediate cartridges offer a substantial step up in terminal performance compared to traditional intermediate military loads.
Cor-Bon came out with a 123-grain Barnes load in its DPX line, but it's very expensive. So what can your typically frugal 7.62x39 shooter do to improve the performance of their ammunition without busting the bank? Well, quite a bit actually if you have some basic reloading equipment and a quantity of steel case ball.
Making what I call "Moscow match" ammo is fairly easy to do and is based upon the same procedure military rifle teams used in years past, pulling the 173-grain FMJ-BT from issue 7.62x51 M118 Special Ball and replacing it with a more accurate Sierra 168-grain MatchKing.
Some shooters would dump and then carefully re-measure the powder charge while others would simply seat the new bullet on top of the existing charge. The result was a more accurate load for military competition.
Basically the same thing can be done with 7.62x39 ball. All you need are a quantity of 7.62x39 ball, a reloading press, a bullet puller, 7.62x39 dies and replacement projectiles.
Good choices include Hornady's .310-diameter 123-grain spire point and V-MAX; Sierra's .311-diameter 12-grain Pro Hunter; Speer's .310-diameter 123-grain Hot-Cor softpoint; and Winchester's .310-diameter 123-grain PowerPoint. More expensive are Barnes' .310-diameter 108-grain RRLP frangible and 123-grain Triple-Shock and TAC-X.
Start by pulling the factory FMJ projectile. For very small quantities an inertia puller will work, as long as your arm holds out. A press-mounted bullet puller such as Hornady's Cam-Lock makes the process quicker and easier.
Once the projectile is pulled, you have two options: load a bullet of identical weight and bearing surface as the one pulled or dump the existing powder charge and reload the case with a new powder charge and projectile.
That's it. Sound simple? It is, but you do need to keep a few things in mind. For the sake of safety I recommend weighing the powder charges and finding out what the average is. Then reduce this by 10 percent and load five rounds. If there are no pressure signs, then load another five with the factory charge. If again there are no pressure signs then you are good to go.
If you desire to load a different weight projectile, a projectile with a longer bearing surface or a solid copper projectile then you need to go to your loading manuals to find an appropriate powder charge. Otherwise pressure can spike.
Careful bullet selection and a little work is all that's required to turn a large quantity of inexpensive ball into a top performing load. Exterior ballistics? Due to its relatively low muzzle velocity and use of projectiles with very low ballistic coefficients, the 7.62x39 will never be flat shooting. But you can improve the accuracy.
What the 7.62x39 does best though is to put a respectable amount of power in a small package. Teamed with a modern projectile, the 7.62x39 cartridge is capable of fully realizing its potential.