The original intermediate cartridges: while the 7.92x33mm Kurz was groundbreaking, the 7.62x39mm was the real success.
70 years ago 7.92x33mm Kurz weapon systems were just starting to be fielded in numbers on the Eastern Front during World War II. While the weapon systems were important it was the intermediate cartridge they fired that was most noteworthy. Referred to as the Pistolenpatrone M43 (pistol cartridge Model 1943) and later Kurzpatrone 43 (short cartridge 1943) it was a groundbreaking step into the future.
The cartridge was designed by a team of engineers at the Polte ammunition works in Magdeburg in 1938, They basically shortened a 7.92x57mm Mauser case 24mm and added a bit of taper to aid feeding/extracting steel cases. It was topped with a 125-grain FMJ projectile driven to approximately 2247 fps.
While performance was a noticeable step down from the 7.92x57mm Mauser, that was the entire point of the design. It allowed for a smaller and more compact weapon system that recoiled less, was controllable on full automatic and held more ammunition. It also allowed the soldier to carry more ammunition.
Sufficiently accurate and effective at normal infantry distances, it increased a soldier's survivability on the battlefield. All in all it was an effective cartridge with greater range, accuracy and terminal performance than the 9x19mm used in submachine guns but without being excessive like the 7.92x57mm. The 7.92x33mm Kurz would go on to carve its mark on the battlefield.
Indeed its service life has been much longer than most would realize. StG 44s were fielded by the East German Volkspolizei until 1962 and by the 63rd Paratroop Battalion of the Yugoslav People's Army into the 1980s.
Many are still being fielded in combat to this day in the Middle East and Africa. Ammunition remains in production all these years later by Prvi Partizan (PPU) of Serbia and is available commercially. Components are also available and Hornady has produced a 125-grain HP specifically for it.
While the 7.92x33mm Kurz was a success in combat, its greatest legacy is the cartridge developed to counter it, the Soviet 7.62x39mm. The 7.62x39mm is not just a cartridge; it is one of the most significant military cartridges of the 20th Century.
Mated to the RPD, SKS-45 and Avtomat it redrew boundaries around the globe. It toppled old empires and created fresh ones who waved a red banner. In the 1960s and 1970s its distinctive report seemed to scream revolution. A generation of Americans came to know it in the jungles and rice paddies of South East Asia.
Decades after the memories of Vietnam had faded their sons and daughters would meet it in the deserts and mountains of other far off lands. Specifically designed as a compromise, the 7.62x39mm excels at nothing in particular. Yet it's this jack of all trades personality that makes it so affable. Is it perfect? Not hardly. Is it an important milestone in military cartridge development? Without a doubt! The genesis of the 7.62x39mm dates back to July 15, 1943 when the People's Commissariat for Armaments of the Soviet Union discussed the need to develop an answer to the German 7.92x33mm Kurz. It was intended from the outset to chamber the new cartridge in a complex of weapons rather than just a single rifle.
Work was undertaken by a team of gifted engineers and designers. Led by N.M. Elizarov, and advised by the greatest small arms designers in the Soviet Union (including Fedorov himself) they considered 314. possible cartridge designs. Extensive testing eventually led to the 7.62x39mm cartridge we know today being adopted. It went into mass production in March, 1944.
The new design would bridge the gap between the 7.62x25mm used in pistols and submachine guns and the full power 7.62x54mmR rifle cartridge. Developed specifically for use in automatic weapons, it featured a short, aggressively tapered rimless bottleneck cartridge case. This is 1.524 inches long with a base diameter of .447".
To aid reliability, it has a relatively thick .059" rim. The case tapers down to a shoulder diameter of .396" and has a water capacity of 35.6 grains. Neck diameter is ,339" and .311" diameter projectiles weighing 123 grains were utilized. Overall length is 2.205 inches.
The new design would provide a considerable savings in raw materials during the manufacture of propellant, cartridge cases and projectiles compared to the 7.62x54mmR. It would also facilitate a reduction in size and weight of weapon systems while cutting recoil.
Exterior ballistics, while inferior to the 7.62x54mmR, was geared towards actual infantry ranges. Its focus was for use inside 400 meters. As such, it offered an across the board increase in range, penetration and terminal performance over the hot 7.62x25mm submachine gun loads. It was this practical balance of size and performance that would make it so successful.
Like many, I became hooked on this cartridge during the days of ridiculously cheap Chinese ammunition. While the $70 a case ball is long gone, today we have expanding loads never dreamed of in the 1980s. These new loads dramatically increase the terminal performance of this cartridge.
Two which have caught my attention are Winchester's PDX1 and Cor-Bon's DPX. Winchester's PDX1 features a 120-grain hollow point with their Split Core technology. The projectile has a notched jacket and a bonded core to provide a balance between expansion, weight retention and penetration. Advertised velocity of this load is 2365 fps and it has a claimed ballistic coefficient of .248. Cor-Bon's DPX is a very different animal in that it is loaded with a Barnes TSX. This 123-grain monolithic HP is made from solid copper and is famous for its deep penetration and near 100% weight retention. Muzzle velocity of this load is 2300 fps and it has an advertised BC of .275.
The downside to both of these impressive new loads is simply their price. Be ready to open your wallet wide, especially if you want to sock some away. Simple economics make my favorite 7.62x39mm load the Wolf Performance Ammunition 125-grain soft-point in the plain WPA marked black box.
Manufactured at the Barnaul Arsenal in Russia, it provides consistent performance at an economical price. The load is built on a steel cartridge case. Mild steel has proven to work well as a case material for this cartridge design. To prevent corrosion and to aid feeding and extraction, a polymer coating is applied to the case exterior.
A Berdan primer is utilized and the case is charged with a load of extruded powder. A flat-base soft-point projectile weighing 125 grains is seated on top. This has a lead core and a bimetal jacket. Wolf Performance Ammunition lists muzzle velocity as 2330 fps, and I have found a variety of 16-inch Kalashnikov rifles to run +/-40 fps of that figure on average.
Accuracy varies from rifle to rifle, but generally runs between 2.2 and 4 inches for five-shot groups from the bench at 100 yards from a Kalashnikov. Performance when fired into 10% ordnance gelatin at 25 yards is quite acceptable.
The projectile typically penetrates 1 to 2 inches before expanding and shedding its jacket with the largest piece of the lead core penetrating to a depth of 16 to 17 inches. Performance is quite acceptable for an economical load with a traditional lead core projectile. While not a fancy modem "barrier blind" load, it's not priced like one, either and works well on small and medium size game.
7.62X39MM SPECIFICATIONS Case type: Rimless bottleneck Base diameter: .447" Shoulder diameter: .396" Neck diameter: .339" Bullet diameter: .311" Rim thickness: .059" Case length: 1.524 inches Overall length: 2,205 inches Maximum Pressure (CIP): 51,490 psi Maximum Pressure (SAAMI): 45,010 psi SOURCES Wolf Performance Ammunition 888-757-9653 / www.wolfammo.com Cor-Bon 800-626-7266 / www.corbon.com Winchester www.winchester.com