The SR-3 Vikhr was developed by TsNIITochMash (Central Institute for Precision Machine Building) in the early 1990s. It is based on the AS Val silenced assault rifle but lacks an integral suppressor and has a newly-designed folding stock and cocking handle for ease of concealed carry. After the adoption of SR-3, the FSB established new operational requirements with a goal to combine the qualities of the SR-3, AS Val and VSS Vintorez, resulting in a new variant designated SR-3M (СР-3М).
It features a quick detachable suppressor and a redesigned handguard with a collapsible foregrip. The iron sights have also been relocated to the upper front handguard as opposed to being located on the suppressor, apparently for when the gun is used without the suppressor attached. For this weapon a larger 30-round magazine was developed, which can be used also by the AS Val and the VSS Vintorez. [Source: wikipedia]
You can download the papercraft model here: Full Size SR-3 Vikhr Assault Rifle Free Gun Paper Model Download [Box] [Gavitex]