7.62×39mm
The Soviet 7.62x39 rifle cartridge was designed during World War II and first used in the SKS carbine. The cartridge was likely influenced by a variety of foreign developments, especially the pre-war German GeCo GeCo 7.75 x 39 mm experimental round[1], and possibly by the late-war German 7.92 mm Kurz ("Kurz" meaning "short" in German). Shortly after the war the world's most recognized assault rifle was designed for this cartridge: the AK-47. The cartridge remained the standard Soviet load until the 1970s, and is still by far the most common intermediate rifle cartridge used around the world. Its replacement, the 5.45 × 39 mm cartridge, is less powerful but longer ranged (due to its much higher velocity) and is more controllable in full-auto fire (due to the lower recoil). The change was in part a response to the U.S. military's switch from the 7.62 mm cartridge to 5.56 x 45 mm NATO.
The original Soviet bullets are boat-tail bullets with a copper-plated steel jacket, a large steel core, and some lead between the core and the jacket. The cartridge itself consists of a berdan-primed, tapered steel case which seats the bullet and contains the powder charge. The taper makes it very easy to feed and extract the round, since there is little contact with the chamber walls until the round is fully seated. This taper is what causes the AK-47 to have distinctively curved magazines. While the bullet design itself has gone through a few redesigns, the cartridge itself remains largely unchanged.
7.62x39 ammo has typically been amazingly inexpensive for centerfire rifle ammo, about the least-expensive centerfire rifle ammo on the market at long just over 10 cents a round for high-quality imported Russian brands and now 17 cents a round for quality imported ammo after a sharp price rise on mil-spec ammo in this caliber in early 2006. It is even cheaper than most handgun rounds and even some top-dollar target .22 rimfire ammo. However, in 2005/2006, prices began to soar (almost doubling in the US) due to the United States placing a massive order to supply the fledgling Afghan and Iraqi armies[1]. Even so, as of Jan. 2007, it remains by far the least-expensive centerfire rifle ammo on the market. This cartridge has endeared itself to shooters in spite of its limited ballistics, which are analogous to the .30-30, because of the many very-inexpensive good semiauto rifles (notably the SKS) available for it that cost far less than the .30-30 Winchesters and Marlins that long were the least-expensive deer rifles in the U.S., and its minimal recoil.
An imperfect design: M43
Although the new cartridge represented a great leap forward from previous designs, the initial bullet design was flawed. The complete solidity of the M43 projectile causes its only drawback—it is stable even in tissue and begins to yaw only after traversing nearly 30cm of tissue. This greatly reduces the wounding effectiveness of the projectile against humans. Dr. Martin Fackler noted that the wounds from the M43 round were comparable to that of a small handgun round using non-expanding bullets. Unless the round struck something vital, the wound was usually small and quickly healing. Extremity hits were seen as nearly inconsequential. Also the trajectory of the cartridge leaves much to be desired and caused a new form of assault training to be formed for the Soviet army. When the typical Soviet sight zero is used, the round drops markedly at 50 metres, then rises to several centimetres above target at 100 metres, hitting its mark at close to 300 metres and fading quickly after that. The Soviet army was trained to accommodate for this by aiming low and sweeping up through the target while advancing, as seen in Soviet training films. This tactic has been wonderfully adopted by the Chinese given their standard tactic of "the human wave" assault.
Advancements in projectile design: M67
In the 1960s the Yugoslavians experimented with new bullet designs to produce a round with a superior wounding profile to the M43. The Yugoslavian type rounds are known as M67 and incorporate an air gap inside the front of the bullet. This shifts the center of gravity rearward, causing the bullet to destabilize nearly 17 cm earlier in tissue. This causes a pair of large stretch cavities at a depth likely to cause effective wound trauma. When the temporary stretch cavity intersects with the skin at the exit area, a larger exit wound will result, which takes longer to heal. Additionally, when the stretch cavity intersects a stiff organ like the liver or a full bladder, it will cause damage to that organ.
However, without fragmentation, the wounding potential of M67 is mostly limited to the small permanent wound channel the bullet itself makes. While a fragmenting round (like the 5.56 x 45 mm) might cause massive tissue trauma and blood loss (and thus rapid incapacitation) on a lung or abdominal hit, the M67 has a greater chance of merely wounding the target. Still, it is an enormous improvement over the M43 design.
Nearly all modern 7.62x39 mm rounds of civilian or military manufacture are of the M67 variety—a simple boattail FMJ round with a forward air cavity. Notable exceptions are the Ulyanovsk Machine Factory EM1 "match" (which substitutes a nipple for an air cavity and produces a single large temporary cavity in place of two small ones) and the Wolf 150 grain (9.7 g) soft point which behaves much more like a traditional expanding hunting round. Nearly all Jacketed Hollow Point rounds in 7.62 x 39 mm are M67 rounds with a small hole in the front of the jacket—terminal ballistics are nearly identical to their fully jacketed brethren. They are a concession to various hunting laws that forbid FMJ rounds. Of all the tested JHP rounds, only Ulyanovsk EM3 hollowpoints seem to expand at all.
Chinese steel core
Chinese military-issue ammunition in this caliber is M43 style with a mild steel core and a thin jacket of copper or brass. Contrary to common belief, the use of steel was a cost saving measure rather than one to increase the penetration. Additionally, mild steel is not sufficiently hard to grant unusual armor penetrating capability . Despite this, Chinese ammunition is currently banned from importation in the US due to the fact that there are 7.62x39 mm caliber "handguns" and the ammunition is an "armor piercing handgun round" under the U.S. federal legal definition of the word, which is based on materials and bullet design rather than on tested ability to penetrate armor.
Other names for 7.62x39
On some occasions, this ammunition is referred to as 7.62 mm Soviet, 7.62 mm Warsaw Pact rounds, or 7.62 mm ComBloc. It was also known in the United States as .30 Short Russian; the "Short" was to distinguish it from the older .30 Russian (7.62mm Russian), which was the 7.62x54R. (Note that the "R" in 7.62x54r does not stand for "Russian", but rather stands for "Rimmed". It is, however, a Russian made cartridge.)
Since approximately 1990 the 7.62x39 mm cartridge has seen some use in hunting arms in the US for hunting game up to the size of whitetail deer, as it is approximately as powerful as the old .30-30 Winchester round, and has a similar ballistic profile. Large numbers of inexpensive imported semiauto rifles, like the SKS and semi-auto AK-47 clones and variants, are available in this caliber, and the SKS is so inexpensive as to have begun displacing the .30-30 lever-action rifles as the new "poor man's deer rifle" by being much less expensive than the .30-30 Marlins and Winchesters that long had that role. Inexpensive imported 7.62x39 mm ammunition is also widely available, though much of it is of the non-expanding type that may be illegal to use for hunting in some states. However, both some imported Russian ammunition like Wolf brand and American civilian manufacturers which produce both hollow-point and soft-point rounds, suitable and legal for hunting.
Rifles using the M43 round
- SKS
- Pribor-3B Rifle
- AK-47/AKM
- Vz 52/57
- Vz 58
- Rk 62
- RPD
- RPK
- Stoner SR-47
- Rasheed Carbine
- Ruger Mini-30 carbine
- CZ-527 Mini-Mauser style carbine
- Colt Sportster AR-15
Specifications
- Round length: 55.80 mm
- Case length: 38.65 mm
- Rim diameter: 11.30 mm
- Bullet diameter: 7.90 mm
- Bullet weight: 7.97 g
- Nominal charge: 1.60 g; SSNF 50 powder
- Muzzle velocity: 710 m/s
- Muzzle energy: 2,010 J
See also
References
- ^ "US sets up £215m deal for Afghan arms - from Russia", telegraph.co.uk, retrieved 2 Oct 2006
External Links
- Wolf Ammunition catalog of rifle cartridges