The SKS ingame is a Yugoslavian M59/66 PAP, as such, the description and name are wholly incorrect. Try to address that at least in description.
Also, they have been missing a butt plate, which is an integral part of the buttstock (http://www.localnumber69.com/temp/Yugo_SKS.jpg) as seen here. Please see with art team to have this fixed.
These bugs have been persisting since the first day they have been added.
Obtain a SKS ingame, and examine its buttstock.
Yugoslav M59/66s main difference is a 22mm rifle grenade launcher integrated with the top of the barrel. As such, they can launch NATO standard (22 mm) rifle grenades with special blank ammo. When doing so, shooter is provided with a additional extra thickness rubber butt pad as seen here (http://ecx.images-amazon.com/images/I/51vfmnL1CwL.jpg).
The butt pad can be a lootable item that makes the recoil a tiniest bit more controllable, if you decide to make it.