Momentous Metrics

7.92×33 and 7.62×39: Short But Significant

By Mike “Duke” Venturino
Photos: Yvonne Venturino

Two cartridges changed the entire planet’s military organization. Until they were developed, most armies used rifles chambered for full-size rifle cartridges from 6.5 to 8mm. The smallest one used by major combatant nations in World War II was the 6.5×50 Japanese. The longest was America’s .30-06 at 63mm. Germany’s standard was the 7.92×57, which in this country is most commonly referred to as 8mm Mauser.

The military thinkers who developed those large chamberings around the turn of the 19th Century assumed large formations of troops would be ordered to set their sights identically and then fire on command at targets far away — maybe even thousands of yards distant. This seldom worked out!

The SKS (bottom) was one of the first developed for the 7.62×39. A current American-made
rifle chambered for it is the Ruger Mini-30 Tactical (top).

Kalashnikov’s ubiquitous AK-47 cemented the 7.62×39’s standing worldwide. Photo: Will Dabbs, MD

The Kurz Concept

Germany was the instigator of the revolution of which today are called “intermediate cartridges.” The Wehrmacht’s studies showed most combat between rifle-armed troops occurred within 400 yards. Therefore the excessive use of strategic materials such as went into manufacturing heavy bullets and large volume cases — as needed for cartridges designed to reach out thousands of yards — was a waste. That’s not to mention the hefty powder charges needed to push a bullet out a mile or two.

So about mid-WWII, the Germans introduced a new concept. They kept the 7.92 bullet diameter (.323″) but reduced bullet weight from 198 to 123 grains and case length from 57 (2.244″) to 33mm (1.299″). Nominal muzzle velocities went from 2,540 fps for the full-power load to 2,350 fps for the new intermediate round.

The rifles German inventors developed for this new cartridge went by several names. First was MKB42 (1942) then there followed MP43, MP44, and Stg44. “Stg” meant Sturmgewehr (literal translation: “Storm Rifle”).

The Wehrmacht envisioned the STG-44 (center) as replacing both the K98k (top)
and the MP40 SMG (bottom). It never did.

Long to short: The first two intermediate military cartridges, with their predecessors.
Left, Germany’s 7.92×57 (rear) and 7.92×33 (front). At right are the Soviet 7.62x54R
(rear) and 7.62×39 (front.)

Soviet “Refinement”

I have an MP44 in my modest WWII collection. It has a 16.5″ barrel with a 37″ overall length. Those dimensions are close to the United States’ M1. 30 Carbine. However, at 11 lbs. my MP44 is almost twice as heavy as a .30 Carbine. Magazine capacity is 30 rounds and all versions were select-fire by the simple push of a button. German doctrine called for them to be used semi auto most of the time — with full auto being reserved for when the enemy was about to overrun German positions.

Of course the Soviet Union was never above “borrowing” ideas, even to the point of claiming them as their own. Within a year of the battlefield appearance of Germany’s new 7.92×33 cartridge, the Soviets had one similar. They stayed with their favored 7.62 (.310″) for bullet diameter, but matched Germany for bullet weight at 123 grains (as well as velocity at 2,350 fps).

Prior to this the Soviets had held onto the full-power, 1890s vintage Mosin-Nagant cartridge, the 7.62x54R. With their new intermediate innovation, the same rimless case head used by Germany on both their 7.92 rounds was adopted, but for some reason the Soviets lengthened their version to 39mm (1.528″).

The Soviet Union developed a semi-auto carbine to go with their new cartridge, but if it saw action in WWII it had to have been in the closing days. Designed by Sergei Simonov, it was called the SKS. Many Americans first heard of it when it was being fired upon U.S. soldiers by communist troops in Vietnam. Being semi auto only, American soldiers were permitted to bring them home as trophies. Then late in the 20th Century untold thousands of SKSs were imported from various Soviet Bloc nations. I remember seeing them advertised for as little as $69.99.

With only a 10-round magazine capacity and it being loaded from the top by means of stripper clips, the SKS has avoided most of the “assault rifle” controversy. Ruger has been chambering for the 7.62×39 for about 30 years in their Mini-30.

However, the SKS was a mere blip on the 7.62×39 radar screen. What made the cartridge so important was an estimated 100 million AK47s have been produced worldwide. Of course, it was developed in the Soviet Union but they passed out its blueprints far and wide and the quality of manufacture has varied likewise.

True AK47s are extremely rare in the United States because they’re select-fire — requiring registration with the Federal Government. The many, many thousands we see in our gun stores nowadays are semi auto only, and in the truest sense are AK47 facsimiles. Considering all AK47 makers worldwide, the 7.62×39 must be the world’s most popular rifle cartridge.

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