July 27, 2017
Ammunition for the AK centers on two cartridges, the original 7.62x39mm round and the subsequent 5.45x39mm. Although, it should be remembered that AKs of one type or another have also been chambered for two NATO calibers — the 5.56 NATO round (as seen in the current Russian Izmash AK101 and AK102 rifles, with 415mm and 314mm barrel lengths, respectively) and the 7.62 NATO cartridge found in the Yugoslavian M77B1 Light Machine Gun (LMG). In addition, 5.56 NATO-chambered Kalashnikov-type rifles have been produced, principally for export, by Romania (Model 97), Poland (Model 96 Beryl and Mini-Beryl), Finland (Sako M95) and the Norinco Type 97 bullpup from the People's Republic of China.
Studying and collecting military small arms ammunition is a fascinating pastime. Except for a few rare
specimens, it's a lot less expensive to accumulate cartridges than the rifles for which they are chambered. As with stamp collecting, a great deal can be learned about a nation's history, culture and degree of industrial development by studying the cartridges they have manufactured. Even more important, a detailed examination of small arms cartridges is a useful tool of the technical intelligence community. During the 1980s civil war in El Salvador, I was able to track which Com-Bloc countries were supplying the FMLN Marxist terrorists and how this changed over time by studying the headstamps of captured ammunition. For these purposes, I have provided a unique identification chart of the two principal AK cartridges at the end of the text. It's hoped that this may assist Coalition troops who read this in identifying ammunition caches, as well as stimulating budding cartridge collectors. But first let's take a close look at the history of these two cartridges and their respective wound-ballistics potential.
Attributed to designers Nikolai M. Elizarov and Boris V. Semin, Soviet historians contend that work on the M43 (Model 1943) 7.62x39mm cartridge began in 1939, was temporarily suspended because of the Great
Patriotic War and then recommenced and finalized in 1943. Others have stated that it was derived from the German 7.92x33mm Kurz Patrone (short cartridge) developed for the world's first assault rifle produced in significant quantities, the World War II MP43/44 (StG44/45). This latter scenario is highly unlikely, as the Soviets would have required specimens of 7.92x33mm Kurz ammunition at least a year or two prior to their adoption of the 7.62x39mm round in 1943, well before the MP43 was fielded on the Osten front (first reported use was December 1942).
Whatever the case, the Soviet M43 cartridge is a true intermediate assault-rifle round. The first prototypes featured cases that were 40.29mm in length (thus: 7.62x41mm). The case was trimmed to 38.6mm, as the original projectile proved unsatisfactory; a new bullet was adopted that required a shorter case.
The following countries have manufactured ammunition in this caliber: Austria, Belgium, Brazil, Bulgaria, Cuba, Czechoslovakia, East Germany, Egypt, Finland, France, Hungary, Iraq, Israel, Netherlands, North Korea, Norway, Peru, Poland, Portugal, People's Republic of China, Romania, South Africa, South Korea, Sweden, Syria, United States, U.S.S.R., West Germany and Yugoslavia. In addition to Full Metal Jacket (FMJ) ball ammunition, it has been produced with
hollowpoint, softpoint, tracer, API (armor-piercing incendiary) and IT (incendiary tracer) projectiles.
Special-purpose loads have included heavy subsonic ball (for use with sound suppressors), practice blanks, short-range loads and drill rounds. Ball ammunition will be encountered in two configurations. Most prevalent is a 123-grain boattail bullet, which usually consists of a copper-washed steel jacket, lead and antimony sleeve and a mild steel core (Soviet Type PS). Yugoslavia's M67 ball ammunition, as well as that of several other countries, uses a flat-based bullet of approximately the same weight with a copper-alloy jacket and lead core. Muzzle velocity of both types is between 2,330 and 2,400 fps.
In its boattail configuration, the 7.62x39mm FMJ bullet travels point-forward about 10 inches in soft tissue before significant yaw occurs. At that distance the bullet will yaw to less than 90 degrees, then come back down to a point-forward position and finally yaw 180 degrees — ending its travel in a base-forward position. Bi-lobbed yaw cycles of this type are commonly observed with pointed, nondeforming bullets. Total penetration in living tissue is almost 29 inches. Abdominal shots usually exhibit no greater tissue disruption than that produced by a .38 Special bullet fired from a handgun since, after 10 inches of travel without yawing, the bullet has generally passed through the abdominal cavity. However, of course, this round is capable of inflicting such damage at far greater ranges than a handgun would. When I was working at the Wound Ballistics Laboratory at the Letterman Army Institute of Research in San Francisco, we tested the lead-cored, flat-base Yugoslav bullet and found it to be considerably more effective. It commences its yaw cycle after only three to four inches of penetration. Once again, the yaw cycle is generally bi-lobed. The bullet reaches its maximum penetration of 23 to 26 inches traveling base-forward, somewhat flattened and retaining almost all of its original weight (two or three small fragments are shed in the area of maximum cavitation).
Although the flat-based 7.62x39mm bullet is shorter (.930 inch) than the more common boattail projectile (1.040 inch), it will be expected to cause more damage to the abdomen, liver, spleen or pancreas because the bullet passes through these organs at a large yaw angle. If we have neither mushrooming nor fragmentation, yawing is all that remains to maximize tissue disruption and enhance the bullet's performance — provided that we do not sacrifice penetration.
The 5.45x39mm Cartridge
Development of the 5.45x39mm cartridge was quite obviously in direct response to the 5.56x45mm NATO M193 56-grain ball round, deployed with arguable success in Vietnam. Research on the concept began in the late 1960s. Engineer Viktor Sabelnikov headed the project.
The rimless 5.45x39mm bottlenecked steel case is actually 39.6mm in length. The 53-grain boattail bullet has a gilding-metal-clad steel jacket. The unhardened flat-tip steel core is covered by a lead sleeve that does not fill the entire interior of the jacket, leaving a hollow cavity inside the nose — the focal point of the imbroglio over wounding potential.
Large-caliber steel cores, such as the hardened penetrator of the U.S. .50-caliber AP round, can be screw-turned to a pointed tip without too much trouble. It would be difficult to screw-turn, or even swage, a pointed tip on the 5.45x39mm bullet's small steel core. I personally believe it was simply more cost-effective to fabricate a flat-tipped core and leave an air pocket under the jacket's tip as long as it did not affect the projectile's aerodynamic qualities. The fact that it might enhance the bullet's wounding potential was, in this instance, merely coincidental. (Some reliable Russian sources plainly state the design of the 7N6 projectile was in part to enhance terminal performance.)
There is nothing new about this type of construction. During World War I, the British .303-inch Mark VII bullet contained an aluminum (and sometimes fiber, wood, pottery or compressed paper) filler in front of its lead and antimony core, directly under the jacket's tip. This was principally an attempt to reduce the bullet's weight.
With one peculiar exception, the 5.45x39mm bullet exhibits no more, or less, than the usual performance characteristics expected from a nondeforming Full Metal Jacket (FMJ) military bullet. There is a rather typical bi-lobe yaw cycle in soft tissue, with the bullet ending its travel base-forward. Yaw commences after only about three inches of penetration in living tissue. This will increase the tissue disruption, even in many extremity hits on the arms or legs.
In all tests performed on this cartridge by Dr. Martin L. Fackler at the Wound Ballistics Laboratory, the angle of this bullet's long axis after it came to rest in the tissue simulant showed a change in direction of between 80 and 90 degrees. Curvature of a boattail FMJ bullet's path is not uncommon, but always sporadic and generally no more than 45 degrees. X-rays taken at the Wound Ballistics Lab of recovered 5.45x39mm bullets showed that the lead sleeve flowed asymmetrically forward into the jacket tip after rapid deceleration upon striking tissue, to unbalance the projectile and possibly initiate its right-angle turn. Curious, but the results are less than awesome. When the AK74 rifle and its cartridge first surfaced in Afghanistan, rumors were widely circulated that its muzzle velocity exceeded 4,000 fps, and that it produced massive tissue damage. Obviously, this was not true. The performance approximates that of the M193 round, albeit for somewhat different reasons.
The ammunition used in my tests and evaluations of rifles chambered for the 5.45x39mm cartridge was imported by Wolf Performance Ammunition and manufactured at Tula Cartridge Works in Russia. Headstamped "5.45X39 WOLF," the lacquered steel case has a red case mouth sealant and primer annulus. The flattened ball, single-base nitrocellulose propellant has a charge weight of 201/2 grains, nominal. Although the packaging stated the projectile to be 60 grains, it was in fact 59 grains, nominal.
It is claimed that this bullet provides the same wound-ballistic characteristics as the standard Russian 7N6 military round, but I have not confirmed this. Chronographing this ammunition through a Polish Tantal rifle produced the following results. All chronograph tests were conducted with a PACT MKIV timer with chronograph and cyclic rate counter. Velocities were measured at a distance of 10 feet from the muzzle. The ambient temperature at the time of the tests was 79 degres Farenheit.
The average velocity from a 161/4-inch barrel was about 3,020 fps. The extreme spread of velocities varied from 57 to 74 fps. The standard variation ranged from 18 to 28 fps, while the MAD (Mean Absolute Deviation) as a percent of the average velocity was about .55 percent; that is excellent and indicates almost match-grade ammunition.
Accuracy has long been an area of criticism with the Kalashnikov series. Very rarely will any AK shoot better than three or four MOA. Ammunition is usually part of the problem, as true match-grade ball ammo is rarely available. In addition, the AK's exceptional reliability is partially a result of manufacturing tolerances designed to maximize reliability under adverse conditions. This, without doubt, affects the rifle's accuracy potential.
However, the question remains: how much accuracy is necessary, or even desired, for a battlefield infantry rifle? In most instances the Kalashnikov is "good enough for government work" with the usual high level of reliability and accuracy intended for the battlefield, not bullseye paper targets.
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