SKS
The SKS is a semi-automatic carbine designed by Soviet small arms designer Sergei Gavrilovich Simonov in the 1940s.
The SKS was first produced in the Soviet Union but was later widely exported and manufactured by various nations. Its distinguishing characteristics include a permanently attached folding bayonet and a hinged, fixed magazine. As the SKS lacked select-fire capability and its magazine was limited to ten rounds, it was rendered obsolete in the Soviet Armed Forces by the introduction of the AK-47 in the 1950s. Nevertheless, SKS carbines continued to see service with the Soviet Border Troops and second-line and reserve army units for decades.
The SKS was manufactured at Tula Arsenal from 1949 to 1958, and at the Izhevsk Arsenal from 1953 to 1954. Altogether, the Soviet Union produced 2.7 million SKS carbines. Throughout the Cold War, millions of additional SKS carbines and their derivatives were also manufactured under license in the People's Republic of China, as well as a number of countries allied with the Eastern Bloc. The SKS was exported in vast quantities and found favour with insurgent forces around the world as a light, handy weapon which was adequate for guerrilla warfare despite its conventional limitations.
Beginning in 1988, millions have also been sold on the civilian market in North America, where they remain popular as hunting and sporting rifles.
Design
The SKS is a gas-operated carbine with a conventional wooden stock and a fixed ten-round box magazine enclosed inside the receiver. It has a tilting bolt and a gas piston operating rod that works to unlock and cycle the action via gas pressure. When a round is discharged, some of the gases in the bore are diverted through the gas port and impinge on the head of the piston. The piston is driven rearwards and the tappet strikes the bolt carrier; a spring returns the tappet and piston to their forward position. The bolt carrier is driven rearwards, which causes it to lift and unlock the bolt and allowing it to be carried rearwards against the recoil spring. This allows the fired cartridge case to be ejected, and as the bolt is returned to its original position by the recoil spring it strips a new round from the magazine and chambers it.The SKS magazine can be loaded either by hand or from a stripper clip which seats in the bolt carrier. To load the rifle, the cocking handle on the right of the bolt is retracted, and if the magazine is empty the bolt will remain at the rear. When the magazine is fully loaded, the bolt is pulled slightly back then released, at which time it will chamber the first round. Cartridges stored in the magazine can be removed by pulling back on a latch located forward of the trigger guard.
When the magazine is expended, a small stud engages the bolt and holds it to the rear, in effect functioning as a bolt hold open device. After the magazine platform is depressed by the insertion of ammunition, the stud continues to hold the bolt at the rear of the receiver until the bolt is pulled slightly back, at which time it drops into its normal position and releases the bolt to chamber the next round.
While early Soviet models had spring-loaded firing pins, which held the pin away from cartridge primers until struck by the action's hammer, most variants of the SKS have a free-floating firing pin within the bolt. Because of this design, care must be taken during cleaning to ensure that the firing pin can freely move and does not stick in the forward position within the bolt. SKS firing pins that are stuck in the forward position have been known to cause accidental "slamfires". This behavior is less likely with the hard primer military-spec ammo for which the SKS was designed, but as with any rifle, users should properly maintain their firearms. For collectors, slamfires are more likely when the bolt still has remnants of cosmoline embedded in it that retard firing pin movement. As it is triangular in cross section with only one way to properly insert it, slamfires can also result if the firing pin is inserted in one of the other two orientations.
In most variants, the barrel is chrome-lined for increased wear and heat tolerance from sustained fire and to resist corrosion from chlorate-primed corrosive ammunition, as well as to facilitate cleaning. Chrome bore lining is common in military rifles. Although it can diminish accuracy, the effect in a rifle of this type is limited.
The front sight has a hooded post. The rear sight is an open notch type which is adjustable for elevation from. There is also an all-purpose "battle" setting on the sight ladder, set for. This is attained by moving the elevation slide to the rear of the ladder as far as it will go.
All military SKSs have a bayonet attached to the underside of the barrel, which is extended and retracted via a spring-loaded hinge. Both blade and spike bayonets were produced. Spike bayonets were used on the 1949 Tula Russian SKS-45, the Chinese Type 56 from mid 1964 onward, and the Albanian Model 561. The bayonet on the SKS in both the closed/deployed positions also serve to apply tension on the cleaning rod to keep it firmly in place. As well, the bayonet on the SKS rifles help keep the rifles evenly balanced and keeps muzzle climb down.
The SKS is easily field stripped and reassembled without specialized tools, and the trigger group and magazine can be removed with an unfired cartridge, or with the receiver cover. The rifle has a cleaning kit stored in a trapdoor in the buttstock, with a cleaning rod running under the barrel, in the same style as the AK-47. The cap for the cleaning kit also serves as a cleaning rod guide, to protect the crown from being damaged during cleaning. The body of the cleaning kit serves as the cleaning rod handle. In common with some other Soviet-era designs, it trades some accuracy for ruggedness, reliability, ease of maintenance, ease of use, and low manufacturing cost.
Development history
The Soviet Union utilized a number of semi-automatic as well as select-fire rifles during World War II, namely the AVS-36, SVT-38, and SVT-40. However, the primary service rifle of the Red Army remained the bolt-action Mosin–Nagant, which fired the powerful but heavy 7.62×54mmR round. Even prior to the war, the Red Army had recognized that these weapons were obsolete and initiated a program to modernize its existing small arms, although this was interrupted by the German invasion of the Soviet Union in 1941. Among the military development programs the Soviet Union had monitored in other countries were the Finnish, Swiss, and German developments in intermediate rifle cartridges. These had limited range and muzzle velocity compared to the 7.62×54mmR and other contemporary rifle rounds such as the 7.92×57mm Mauser and the.30-06 Springfield, but also possessed numerous advantages: they were cheaper to manufacture, permitted easier weapons handling due to their much-reduced recoil and muzzle blast, and enabled infantry to carry more due to their small size and light weight. They could also be fired from shorter and lighter rifles. The Red Army's interest in an intermediate cartridge was piqued when stocks of 7.92×33mm Kurz ammunition were captured from the Wehrmacht, and by the end of 1943, Soviet technicians had developed a similar cartridge based closely on the German design, the 7.62×39mm M43. Early trials showed that the new round had the penetrative capacity to pierce three panels of plywood, each of 2.25 cm thickness, at a six hundred meter range. Red Army officials believed this was more than enough power to wound or kill a soldier at typical battlefield range. Limited production of the new ammunition type commenced in 1944.Hurried efforts were made to introduce a rifle capable of firing the new cartridge, and the first prominent design was offered by Sergei Gavrilovich Simonov. This was known as the Samozaryadny Karabin sistemy Simonova, or "Simonov's self-loading carbine system" Simonov had already been working on a semi-automatic carbine chambered for a lighter cartridge as early as 1941, owing to recent complaints about the effectiveness of the SVT-40. In fact, one of his earliest prototypes was chambered for the 7.62×25mm Tokarev pistol cartridge, which was also used in the PPSh-41 submachine gun. He also built at least one prototype chambered for the larger 7.62×54mmR cartridge. Unlike previous Soviet semi-automatic rifles, these utilized fixed five or ten-round magazines loaded from stripper clips. They were also distinguished by a large muzzle brake and a fixed gas system covered with a metal shroud. Simonov's design was based on the operating mechanism of the PTRS-41 anti-tank rifle he'd previously developed for the Red Army the same year. On 1 July 1941, the Artillery Committee of the Red Army noted in its records that the Simonov's self-loading carbine, designated SKS-41, satisfied its basic "tactical and technical requirements". The Committee praised the SKS-41 for its light weight and the design of its fixed magazine; it recommended that 50 pre-production models with ten-round magazines be presented to the Red Army for trials. The SKS-41 was to be chambered for the 7.62×54mmR cartridge for logistical reasons, as the Soviet government wished to adapt its existing rifle barrel production lines for the new carbine.
Red Army evaluation of the SKS-41 prototypes was shelved due to the German invasion, and did not resume until Simonov rechambered his weapon to accommodate the 7.62×39mm cartridge in 1944. He also made a number of other detail improvements to his original carbine, omitting the large and unwieldy muzzle brake, adding a folding bayonet, and replacing the metal gas system shroud with a removable wooden upper handguard and gas tube which housed the gas piston. The gas tube and upper handguard could now be removed as needed to access the gas port and piston for cleaning. The appearance of a 7.62×39mm prototype revived interest in Simonov's design, as only he and one other weapons designer, Alexey Sudayev, were able to produce rifles chambered for the new round on short notice. Sudayev's prototype was a less conventional, more compact assault rifle which more closely resembled the later AK-47. A second 7.62×39mm semi-automatic carbine contender was later offered by Mikhail Kalashnikov; this was based on the operating system of the M1 Garand. Kalashnikov's carbine appeared too late to participate in the Red Army's initial evaluation, and was rejected as the decision had already been made to submit the SKS for field trials.
The SKS was light, simple, and considerably shorter than the Mosin–Nagant, which made it easier to handle in dense foliage and urban environments. Simonov deliberately designed the SKS with loose-fitting parts, making it less likely to jam when dirty or inadequately lubricated. This was a notable departure from the relatively tight tolerances on the previous generation of Soviet semi-automatic rifles, and was also part of the design process of the AK-47. The SKS was officially designated as a carbine, although it did not fulfill the same role as the M1 carbine used in the United States Army at the time, and more resembled a traditional infantry rifle both in terms of design and envisaged role. Simonov's early 7.62×39mm models were quickly pressed into service with troops of the 1st Belorussian Front during the final months of World War II. The SKS was still undergoing active field trials when Germany surrendered to the Allies in May 1945. At the war's end, the trials commission in the 1st Belorussian Front recommended the carbine be accepted into general service as the SKS-45. Mass production was delayed while the SKS underwent minor technical changes and alterations as a result of its trial performance during the war. By the end of the 1940s, it finally superseded the various models of the Mosin–Nagant as the standard Soviet infantry rifle.
The AK-47 assault rifle and the RPD machine gun, both firing the same 7.62×39mm cartridge, were introduced into Soviet service around the same time to complement the SKS. During the 1950s, the Soviet Army rapidly mechanized its existing infantry formations, shifting primarily from light infantry on foot to a much more mobile force deploying from armored vehicles. This fundamental shift in tactics called for large volumes of automatic fire to be delivered from moving vehicles, and the AK-47, with its select-fire capability, compact size, and larger detachable magazine, was more appropriate for this role than the SKS. As a result, the AK-47 gradually replaced the SKS as the standard service rifle of the Soviet Army throughout the 1950s. A US Army review of Soviet tactics and weapons found that "the SKS was phased out of infantry use in the late 1950s, not because of any inherent faults, but because a radical change in Soviet tactics rendered it obsolete." However, even at the time of its introduction, Soviet military strategists had always desired an infantry rifle with more firepower than the SKS. They needed a weapon that better permitted the infantry to give massed automatic fire during an offensive. Military historian Edward Ezell suggested that the SKS was always intended to be an interim solution, and the Soviets simply pushed it into production because they wanted any rifle chambered for the 7.62×39mm cartridge in general service as soon as possible, while a select-fire assault rifle was still being perfected. Small arms expert John Walter concurs in his works, noting that the SKS was "ordered into series production largely to gain experience with the new M43 intermediate ammunition and buy time while a true assault rifle was developed." There was a proposal that the SKS could be retained as a dedicated marksman rifle, but it failed to meet the accuracy requirements and this role was subsequently filled by a new weapon, the SVD.
In June 1955, the Soviet Union hosted a military and civilian delegation from the People's Republic of China led by General Zhao Erlu. The Chinese delegation was given a tour of the Tula Arms Plant, where they observed the assembly of SKS carbines. General Erlu expressed an interest in acquiring the technology for the SKS, as China had previously only been granted a license to produce the Mosin–Nagant, which was by then a rather antiquated design. After negotiations between Mao Zedong and Soviet premier Nikita Khrushchev, the Soviet Union agreed to transfer the technology for the SKS, as well as the AK-47 and the 7.62×39mm cartridge. Parallel production lines for the SKS and the AK-47 were set up in China the following year. Chinese production of the SKS continued for decades after it ceased in the Soviet Union, and over nine million had been manufactured as the Type 56 carbine in that country by the 1980s. Eighty Chinese factories eventually tooled up to produce the Type 56 carbine, although the primary production line was established at the Jianshe Machine Tool Factory, officially designated Factory 296. The Chinese carbines were mostly identical to the Soviet weapon, although their receivers were produced with carbon steel rather than the Soviet specified chrome-nickel alloy steel. Over the course of production, the Type 56 carbine was also manufactured with a greater percentage of stamped as opposed to machined parts.
In terms of production numbers, the SKS was the ninth most produced self-loading rifle design in history. Nearly all the Warsaw Pact member states adopted the SKS at one time or another, and technical specifications to produce the carbine were shared with the German Democratic Republic and Romania. With the assistance of Soviet or Chinese technicians and generous military grants, armaments factories producing SKS carbines were later established in North Vietnam, North Korea, Yugoslavia, and Albania as well.
While remaining far less ubiquitous than the AK, both original SKS carbines and foreign variants can still be found today in civilian hands as well as in the arsenals of insurgent groups and paramilitary forces around the world. The SKS has been circulated in up to 69 countries, both by national governments and non-state actors. In 2016, it remained in the reserve and training inventories of over 50 national armies.