WW2 had brought about dramatic leaps in arms technology. Aircraft had received jet engines, and tanks the widespread adaptation of sloped armor, but infantry weapons were lagging behind. Entering into the war, only the US had a standard issue rifle capable of semi-auto fire, with all other nations having slow, bolt action rifles that required a bolt to be manually cycled after every shot to fire again. In the latter half of WW2, new weapons would begin to be created, with one in particular being quite advanced. The German STG-44 was the first true assault rifle, and defined the category with it’s use of intermediary cartridges.

The STG-44, a German WW2 weapons that bears a close outward resemblance to the weapons of today.

Up until this point, armies had operated with two main types of cartridges (Bullets): Full power rifle ammo, and pistol ammo. Rifles, the standard issue weapon to infantry, fired a large, powerful round, usually around or exactly 0.3 inches or 7.62mm wide. They would be quite long as well, with the US for example using a 63mm long bullet with a 7.62mm diameter, making it 7.62x63mm (It was usually known as .30-06, pronounced 30-aught-six.). Other nations used similarly long cartridges, usually at least 50-56mms long. This length gave room for plenty of powder, making these bullets deal heavy damage and have heavy recoil. While the extra power was perfect for snipers and machine gunners, the rounds performed best at a distance of over 2 km, well over the effective range of the average infantry rifle at 1 km. Adding to that,, most fights took place at a distance of only a couple hundred meters. This meant that only snipers and machine gunners could make the most out of these rounds, and for everyone else, it was just excess recoil. Making automatic weapons that fired these bullets from regular rifles was all but impossible as well, as the recoil was completely uncontrollable and the high energy generated stressed the gun. These rounds had many other drawbacks as well, such as weight, carrying capacity, and lower magazine capacity.

.30-06. It’s big and powerful, but the recoil is… unpleasant.

Pistol bullets were far shorter than rifle rounds, and partially compensated for the lower power with larger bullets. While 7.62mm is fairly high power for a rifle cartridge, 9x19mm, the most common pistol cartridge in the world today, is considered somewhat weak as a pistol cartridge. Most pistol cartridges were and are only somewhere around 20mms long, giving them fairly low amounts of power, and therefore making them ill suited for long range engagements. They were and are used successfully in sub machine guns (SMGs), but SMGs are mostly for close to medium range engagements. For a truly universal weapon, a middle ground between the excessive power of the rifle round and the low energy pistol round would need to be found.

Three pistol cartridges, with 9mm on the right. Short and controllable, perfect for an emergency use secondary pistol or an urban combat SMG, but a poor performer at range.

The STG-44 used a novel round: 7.92x33mm kurz (Kurz means short.). The German’s full power rifle round was 7.92×57 Mauser, or just 8mm Mauser. Like all other high power rifle rounds, it was strong but had heavy recoil. The STG obviously wouldn’t work with such an overkill round, so an intermediary cartridges was made, in the form of 8mm Kurtz. Due to the shorter length, the new round was lighter, easier to carry, allowed for a higher capacity magazine, and most importantly, allowed for controllable automatic fire while maintaining rifle grade ballistics. This was the defining attribute of the weapon, and would make it the grandfather of all future assault rifles. For the Germans, however, such a wonder weapon was too little too late, as WW2 was already lost for them by the time the weapon debuted in 1943-44. But such an innovation did not go unnoticed…

8mm Mauser, 8mm kurz, and 9x19mm. The excessive power of the behemoth to it’s left has been dampened, while not yet dipping into the weakness of the pistol cartridge to it’s right.

Soviet innovations after the war: The SKS and AK-47

The soviets had been developing their own intermediary cartridge during the war, which would become 7.62×39. By the end of the war, they had developed the SKS, which pulled from some earlier designs and was a 10 round, semi-auto rifle chambered in the new intermediary cartridge. Although it was not automatic, the smaller, lighter round made it easier to shoot and keep on a target. But by the time it was officially adapted in 1949, it was already starting to become obsolete, due to the invention of the Ak-47.

The SKS. Very much fits into the WW2 era.

The AK-47

Developed in 1947, the AK pulled design inspiration from the STG and the M1 Garand, which was the semi-auto rifle the US was using. Like he STG, it had a 30 round magazine, was capable of both select and automatic fire, and was chambered in an intermediary cartridge, 7.62×39. The initial design wasn’t quite optimized for mass manufacturing, but the soviets decided to just start getting them out and fix that problem later. Through the 1950s, it would push the SKS into moderate obsoleteness.

Everyone knows what this is.

The western side

While the soviet side consisted of one union state and a puppet state or two, the west was a mix of different countries such as the UK, France, the US, the Benelux, and with the war’s end, Italy and West Germany. Every nation was a sovereign state, and every nation used different bullet types and different guns. With the formation of NATO in 1949, if there was to be a collective western response in the case of a soviet invasion, all this would have to change, as supplying the numerous different types of ammo and weapons to soldiers would become a mess. FN, a Belgian company, began to design a new weapon in 1946, the FAL. Initially, it was meant to be chambered in 8mm kurz, but eventually it was decided to switch to a new experimental round, .280 British. In 1950, hoping to begin NATO standardization, the British presented the FAL along with one of their own designs to the US, to compete against their favored rifle. The US “suggested” that the FAL be rechambered for a more powerful .30 caliber, and eventually, a deal was likely struck out where in exchange for rechambering the FAL in to the .30 caliber, the US would adapt the FAL. The FAL was rechambered into the .30 caliber, which eventually became the new NATO standard 7.62x51mm. 7.62×51, while less powerful than what came before such as .30-06, was still a full powered rifle cartridge, giving it a magazine capacity of only 20 rounds compared to the AK’s 30, and automatic fire on these battle rifles was still so uncontrollable that the British removed automatic fire capability on their variant. The Americans, who had broken their promise and went with their own battle rifle, did the same. West Germany had it’s own battle rifle as well, choosing to adapt a competing design after the Belgians refused to give the country that had invaded and robbed their own a decade earlier a license to produce FALs. They kept the automatic fire mode. While NATO wasn’t quite using a universal weapon, they were at least using a universal caliber, but the stubbornness of the US for a big bullet had dealt a serious blow to the practicality of the new weapons.

Known as “The right arm of the free world” due to it’s widespread use, the FAL would remain standard through most of NATO for decades, although it didn’t actually see much real conflict.
The battle rifle the US choose, the M14. While it was supposed to share compatibility in most parts with the M1 Garand, just now with a 20 round magazine and chambered in 7.62 NATO, it was in generally inferior to the M1 in every way except the increased magazine capacity. The FAL was also generally superior.
The German battle rifle, the G3. Not a bad weapon.