Editing SKS (section)

== Design ==
[[File:SKS magazine.JPG|thumb|left|SKS with the magazine closed (top) and open. The magazine release is circled. The release gets pulled back to open the built-in magazine.]]
[[File:SKS bayonet noBG.jpg|thumb|left|An SKS with a blade-type [[bayonet]] in its closed (folded back) and open positions.]]
[[File:SKS field strip.jpg|thumb|left|A [[Field strip|field-stripped]] SKS carbine (disassembled into major components for cleaning).]]

The SKS is a [[Gas-operated reloading|gas-operated]] carbine with a conventional wooden stock and a fixed ten-round box magazine enclosed inside the receiver.<ref name=Jane98/> It has a tilting bolt and a [[Gas-operated reloading#Short-stroke fixed|gas piston operating rod]] that works to unlock and cycle the action via gas pressure.<ref name=Jane98/> 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.<ref name=Jane98/> The piston is driven rearwards and the tappet strikes the bolt carrier; a spring returns the tappet and piston to their forward position.<ref name=Jane98/> 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.<ref name=Jane98/> 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.<ref name=Jane98/>  

The SKS magazine can be loaded either by hand or from a [[stripper clip]] which seats in the bolt carrier.<ref name=Jane98/> 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.<ref name=Jane98/> When the magazine is fully loaded, the bolt is pulled slightly back then released, at which time it will chamber the first round.<ref name=Jane98/> Cartridges stored in the magazine can be removed by pulling back on a latch located forward of the trigger guard (thus opening the "floor" of the magazine and allowing the rounds to fall out).<ref name="pdf.textfiles">[http://pdf.textfiles.com/manuals/MILITARY/united_states_army_tc_9-56%20-%201_october_1969.pdf SKS Rifle: Simonov Type 56] {{Webarchive|url=https://web.archive.org/web/20121224023008/http://pdf.textfiles.com/manuals/MILITARY/united_states_army_tc_9-56%20-%201_october_1969.pdf |date=24 December 2012 }} | TC 9–56, Department of the Army Training Circular, SKS RIFLE, Simonov Type 56, Headquarters, Department of the Army, October 1969</ref>

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.<ref name=Jane98/> 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.<ref name=Jane98/>

While early (1949–50) 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 (especially after long storage packed in [[cosmoline]]) 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" (the rifle firing on its own, without pulling the trigger and often without being fully locked). 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 (notches up), slamfires can also result if the firing pin is inserted in one of the other two orientations.

In most variants (Yugoslav models being the most notable exception), 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 precision, its effect on practical accuracy 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 {{convert|100|to|1000|m|yd}}. There is also an all-purpose "battle" setting on the sight ladder (marked "П", for "Прямой выстрел", meaning "Straight shot"), set for {{convert|300|m|yd|abbr=off}}. This is attained by moving the elevation slide to the rear of the ladder as far as it will go.<ref name="pdf.textfiles" /><ref>{{Cite web |url=http://www.pistolcraft.com/sks/ |title=SKS Instruction Manual<!-- Bot generated title --> |access-date=2012-04-25 |archive-url=https://web.archive.org/web/20120411103553/http://www.pistolcraft.com/sks/ |archive-date=2012-04-11 |url-status=live }}</ref> 

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.<ref name="pdf.textfiles" /> Spike bayonets were used on the 1949 Tula Russian SKS-45, the Chinese Type 56 from mid 1964 onward, and the Albanian Model 561.<ref name="pdf.textfiles" /> The bayonet on the SKS in both the closed/deployed positions also serve to apply tension on the cleaning rod keep it firmly in place.

The SKS is easily field stripped and reassembled without specialized tools,<!-- unfired cartidges are not needed for field stripping, the trigger group does not need to be removed to field strip the gun--> 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.