A relatively new assault rifle that has quickly found admirers around the world, despite lacking a "trendy" design. Weapons of this series are one of the best in their class, renowned for their reliability, accuracy and ease of use. Despite being relatively difficult to obtain in the Zone, this assault rifle is often ordered by experienced stalkers at considerable expense. - Call of Pripyat in-game description
The main drawback of the SGI-5k that it can't mount a SUSAT scope but in almost every other aspect it wins against other assault weapons - it is highly accurate (as good as the TRs-301 and the GP37), it has a shorter reload time than other NATO weapons and is also one of the most (if not the most) durable non-unique weapon in game. The SGI remains accurate and doesn't jam as frequently as other rifles when its condition goes below 70%. It can mount an M203 grenade launcher which makes it even better as a mid-range combat rifle especially when dealing with the more powerful mutants or groups of stalkers. However it is a heavy weapon weighing at a hefty 4 kg when unloaded.
The SGI 5k is commonly used by veteran and expert-ranked members of the Mercenaries and Freedom factions as well as some veteran-ranked soldiers of Monolith during the final battle atop the Chernobyl NPP's superstructure.
It is purchasable from Skinflint after getting a friendly reputation with the Freedom faction.
The player can also obtain an SGI in the Army Warehouses area from the veteran Freedom squad leader that will be ambushed by Skull's company upon entering the area. Although the chances of finding it in good condition is somewhat rare.
Two SGI 5ks can be found inside the Bloodsucker Village being held by two dead Freedom stalkers.
The SGI can be upgraded to mount both an underbarrel grenade launcher and a SUSAT Scope. It shares the same upgrades as all the 5.56mm caliber assault rifles. It performs particularly well for any role it is upgraded to, however for the player's turning speed is slightly, but noticeably reduced which could lead it to being harder to use in close-range combat although it works well as a marksman weapon.
As for the members of Freedom faction, only the experts use this gun. Some experienced Monolith troops around Limansk and certain Mercenaries carry this weapon.
Can be purchased from Ashot after joining the Freedom faction.
A free SGI-5k upgraded to mount a SUSAT scope is given to the player for free upon joining Freedom.
There are a few SGI-5ks found in stashes in the Army Warehouses, one is in a stump where the coordinates are from an unknown stalker and Hog can also provide the location of one in the actual Military base for around 3000 rubles, which is located in the attic of a barracks structure.
In Call of Pripyat, the SGI is fully optimized as an assault weapon. It lost its ability to mount a SUSAT scope although it can now mount a M203 grenade launcher without any modifications. At stock configuration, the SGI has great damage and accuracy, average recoil and above-average durability. The weapon's performance at close range is exceptional, especially when fully modified for maximum firing rate and low recoil, however it is still hampered by the fact that it doesn't support any sights meaning if you attempt to use it long-ranged.
The weapon of choice of veteran Freedom members, as well as Mercenary units – nearly every squad of these factions will have at least one in the squad. Loners may carry this weapon, especially in the Yanov and Pripyat areas. Radiation suit-clad Monolith stalkers also use the weapon.
One can be found in a stash in the outer western area of the Jupiter factory's warehouses behind a red shack (one will get coordinates for it after helping Uncle Yar deal with the mercenaries at Kopachi Village).
The model has a 20 round magazine, but the in game magazine capacity is 30 rounds.
The magazine appears to not be fully inserted into the gun as the extruding plastic line on the magazine isn't touching the receiver. (Confirmed only in ShoC)
The model appears to be mirrored with the folding stock mechanism being on the left side of the gun as well as the cocking handle and some other components which should be on the opposite side. (Confirmed only in ShoC)
The weapon textures are symmetrical on both sides of the gun. On the right side the text can be seen backwards. (Confirmed only in ShoC)
It's likely that the weapon is modelled after the 'PE 90' which is the civilian version of the SG 550 as it contains some features of the PE 90. The weapon does however feature all 3 firing modes in-game which could be a alteration of the textures. This includes single, burst and full auto whilst the PE 90 only supports single fire mode.