During World War II, many countries realized that existing rifles, such as the Mosin-Nagant, were too long and heavy and fired powerful cartridges that were effective in medium machine guns with a range in excess of 2000 meters, creating excessive recoil. These cartridges, such as the 7.92x57mm Mauser, .303 British, .30-06 Springfield, and 7.62x54mmR were effective in rifles to ranges of up to 1,000 metres (1,100 yards); however, it was noted that most firefights took place at maximum ranges of between 100 and 300 metres (110 and 330 yards). Only a highly-trained specialist, such as a sniper, could employ the full-power rifle cartridge to its true potential. Both the Soviet Union and Germany realized this and designed new weapons for smaller, intermediate-power cartridges. The US fielded an intermediate round in the .30 US, now known as the .30 Carbine, and M1 carbines were fielded in large numbers but not as a replacement for the 30-06 round in general use.
The German approach was the production of a series of intermediate cartridges and rifles in the interwar period, eventually developing the Maschinenkarabiner, or machine-carbine, which later evolved into the Sturmgewehr 44 Sturmgewehr, or "assault rifle", which was produced during the war, chambered in the 7.92x33mm Kurz intermediate round.
The Soviet Union type qualified a new intermediate round in 1943, at the same time it began to field the M44 Mosin-Nagant carbine as a general issue small arm. However, the M44, which had a side-folding bayonet and shorter overall length, still fired the full-powered round of its predecessors. A small number of SKS rifles were tested on the front line in early 1945 against the Germans in World War II.[4]
Design-wise, the SKS relies on the AVS-36 (developed by the same designer, Simonov) to a point that some consider it a shortened AVS-36, stripped of select-fire capability and re-chambered for the 7.62x39mm cartridge.[5][6] Of course, this viewpoint is problematic, as the AVS uses a sliding block bolt locking device, while the SKS employs a more reliable tilting-bolt design, which is an entirely different style. As the bolt mechanism is one the defining features of what a rifle "is", having a different bolt means the SKS and AVS merely appear similar in layout, while differing vastly in bolt lockup, caliber, size, and that one has a fixed magazine and the other has a detachable magazine. It also owes a debt to the SVT-40 and M44 that it replaced, incorporating both the semi-automatic firepower of the SVT (albeit in a more manageable cartridge) and the carbine size and integral bayonet of the bolt-action M44.
In 1949, the SKS was officially adopted into the Soviet Army, manufactured at the Tula Armory from 1949 until 1955 and the Izhevsk Mechanical Plant in 1953 and 1954. Although the quality of Soviet carbines manufactured at these state-run arsenals was quite high, its design was already obsolete compared to the Kalashnikov which was selective-fire, lighter, had three times the magazine capacity, and had the potential to be less labor-intensive to manufacture. Gradually over the next few years, AK-47 production increased until the extant SKS carbines in service were relegated primarily to non-infantry and to second-line troops. They remained in service in this fashion even as late as the 1980s, and possibly the early 1990s. To this day, the SKS carbine is used by some ceremonial Russian honor guards, much the same way the M1 Garand is within the United States; it is far less ubiquitous than the AK-47 but both original Soviet SKS rifles and copies can still be found today in civilian hands as well as in the hands of third-world militias and insurgent groups.
The SKS was to be a gap-filling firearm manufactured using the proven operating mechanism design of the PTRS and using proven milled forging manufacturing techniques. This was to provide a fall-back for the radically new and experimental design of the AK-47, in the event that the AK proved to be a failure. In fact, the original stamped receiver AK-47 had to be quickly redesigned to use a milled receiver which delayed production, and extended the SKS carbine's service life.
