| 7.62×39mm | ||
|---|---|---|
Lateral view of a steel-cased 7.62×39mm FMJ cartridge. |
||
| Type | Rifle | |
| Place of origin | Soviet Union | |
| Service history | ||
| In service | 1944–present | |
| Used by | Soviet Union, Warsaw Pact, People's Republic of China, Cambodia, North Korea, Vietnam, Finland, Venezuela, others | |
| Production history | ||
| Designed | 1943 | |
| Produced | 1943–present | |
| Specifications | ||
| Case type | Rimless, bottleneck | |
| Bullet diameter | 7.89 mm (0.311 in) | |
| Neck diameter | 8.60 mm (0.339 in) | |
| Shoulder diameter | 10.07 mm (0.396 in) | |
| Base diameter | 11.35 mm (0.447 in) | |
| Rim diameter | 11.35 mm (0.447 in) | |
| Rim thickness | 1.50 mm (0.059 in) | |
| Case length | 38.70 mm (1.524 in) | |
| Overall length | 56.00 mm (2.205 in) | |
| Case capacity | 2.31 cm³ (36 gr H2O) | |
| Rifling twist | 240 mm (1 in 9.45 in) | |
| Primer type | Boxer Large Rifle | |
| Maximum pressure | 355.00 MPa (51,488 psi) | |
| Filling | SSNF 50 powder | |
| Filling weight | 18.21 gr | |
| Ballistic performance | ||
| Bullet weight/type | Velocity | Energy |
| 123 gr (8.0 g) Full Metal Jacket | 731.5 m/s (2,400 ft/s) | 2,073.6 J (1,529.4 ft·lbf) |
| 154 gr (10.0 g) Spitzer SP | 641.3 m/s (2,104 ft/s) | 2,056.3 J (1,516.6 ft·lbf) |
| 123.5 gr (8.00 g) Full Metal Jacket | 804.7 m/s (2,640 ft/s) | 2,460 J (1,810 ft·lbf) |
| Test barrel length: 415 mm Source(s): Wolf Ammo[1] Omar [2] |
||
The 7.62×39mm round is a rifle cartridge of Soviet origin that was designed during World War II. It was first used in the RPD machine gun. Due to the worldwide proliferation of the SKS and AK-47 pattern rifles, the cartridge is utilized by both militaries and civilians alike.
The 7.62×39mm cartridge was likely influenced by a variety of foreign developments, especially the pre-war German GeCo, 7.75×39mm experimental round,[3] and its developements in the German late-war Intermediate cartridge trials in calibers 7.9mm and 7.62mm. The German adopted 8×33mm Kurz by Polte did not influence developement.
Shortly after the war, the world's most recognized military pattern rifle was designed for this cartridge: the AK-47. The cartridge remained the Soviet standard until the 1970s, and is still one of the most common intermediate rifle cartridges used around the world. It was replaced in Russian service by the 5.45×39mm cartridge which is used by the current issue AK-74 and variants.
The 7.62×39mm cartridge produces significant wounding in cases where the bullet tumbles and fragments in tissue,[4] but produces relatively minor wounds in cases where the bullet exits before beginning to yaw.[5][6] In the absence of yaw, the M43 load can pencil through lung tissue with relatively little injury.[7]
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The original Soviet M43 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, highly tapered (usually 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 (helping to distinguish AK-47s from AK-74s, which feed from a much straighter magazine). While the bullet design has gone through a few redesigns, the cartridge itself remains largely unchanged.
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 very stable, even while traversing tissue. It begins to yaw only after traversing nearly 26 cm (10 in) of tissue [8]. This greatly reduces the wounding effectiveness of the projectile against humans. These wounds were comparable to that of a small handgun round using non-expanding bullets. Unless the round struck something vital, the wound was usually non-fatal, small and quick to heal.
In the 1960s Yugoslavia experimented with new bullet designs to produce a round with a superior wounding profile, speed, and accuracy to the M43. The M67 projectile is shorter and flatter-based than the M43. This is mainly due to the deletion of the mild steel insert. This has the side effect of shifting the center of gravity rearward in comparison to the M43. This allows the projectile to destabilize nearly 17 cm (6.7 in)[9] 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, it will cause damage to that organ.
Even when fragmentation occurs as the bullet yaws, the wounding potential of M67 is mostly limited to the small permanent wound channel the bullet itself makes [10]. The real damage of the M67 is when it yaws. Meanwhile a fragmenting round (like the 5.56x45mm NATO) 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. However, the 5.56x45 will only reliably fragment in close ranges below 125 metres (410 feet).
Many contemporary Russian-made 7.62×39 cartridges, such as those sold under the brand names Wolf Ammunition and Golden Tiger, feature a modified M67 bullet with an airspace cast into the nose or similar ballistic-enhancing tip design (e.g. 8m3) which improve fragmentation and/or tumbling tendencies.
Chinese military-issue ammunition in this caliber is M43 style with a mild steel core and a thin jacket of copper or brass. Chinese ammunition (as well as all other M43 ammunition) is currently banned from importation in the US. U.S. federal law classifies the round as an armor-piercing handgun round. This classification is based on materials and bullet design rather than on empirical ability to penetrate armor.[11]
The 7.62×39mm has 2.31 ml (35.6 grains H2O) cartridge case capacity.
7.62×39mm maximum C.I.P. cartridge dimensions. All sizes in millimeters (mm).[12]
Americans would define the shoulder angle at alpha/2 ≈ 16.4 degrees. The common rifling twist rate for this cartridge is 240 mm (1 in 9.45 in), 4 grooves, Ø lands = 7.62 millimetres (0.300 in), Ø grooves = 7.92 millimetres (0.312 in), land width = 3.81 millimetres (0.150 in) and the primer type is small rifle. According to an American source some barrels can however have a non C.I.P. conform grooves diameter of 7.82 millimetres (0.308 in).[13]
According to the official C.I.P. (Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives) guidelines the 7.62×39mm case can handle up to 355 MPa (51,488 psi) piezo pressure. In C.I.P. regulated countries every rifle cartridge combo has to be proofed at 125% of this maximum C.I.P. pressure to certify for sale to consumers.
On some occasions, this ammunition is referred to as 7.62 mm Soviet, 7.62 mm Warsaw Pact (or WP) being analogous to 5.56 NATO, or 7.62 mm ComBloc. It was also known in the United States as .30 Short Russian/ComBloc; the "Short" was to distinguish it from the older .30 Russian, which was the 7.62x54mmR.
Since approximately 1990, the 7.62×39mm 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 .30-30 Winchester round, and has a similar ballistic profile.[14] Large numbers of inexpensive imported semiautomatic rifles, like the SKS and AK-47 clones and variants, are available in this caliber.
In addition, several AR15 manufacturers such as Olympic Arms, Del-Ton Inc, and ModelOne Sales are producing 16" carbines and 20" to 24" rifle length firearms that can often get very good accuracy to about 1" groups at 100 yards.
Ruger produces the Mini-30 as a 7.62×39mm version of their popular Mini-14 rifle. They also once had their M77 Mark II available in this caliber.
Remington Arms introduced its Compact Model 799 Mini Mauser bolt action rifle chambered in 7.62×39mm in 2006, describing the Mauser action as "sought after by today’s hunters and shooters."[15] The Mauser action is a copy of the Gewehr 98 model rifle's action.
CZ-USA Sells the "micro length Mauser style" bolt action chambered in 7.62×39mm.[16]
Savage Arms has introduced (around 2010–2011) their own bolt action rifle in 7.62x39mm caliber - Model: 10 FCM Scout.[17]
The low cost and high availability of military surplus ammunition makes this cartridge attractive for many civilian shooters, although for hunting large game, many people prefer the 154 gr soft point, which is usually labeled under the Wolf brand. A 126 grain Soft point is labeled under the MFS Brand and features a Zn (zinc) plated steel case instead of the usual lacquer or polymer coated steel.