Century Arms RI4388-N: The VSKA rifle features an all-new bolt carrier, front trunnion, and feed ramp machined from S7 tool steel and specially heat-treated for maximum durability. S7 tool steel provides maximum shock resistance and high compression strength while retaining toughness. The VSKA incorporates a front trunnion and bolt that are machined from billet, a carburized 4140 steel bolt, a chrome-moly 4150 barrel, durable manganese-phosphate finish, and RAK-1 Enhanced Trigger Group for an impressive trigger pull. This special side folding stock VSKA features a Picatinny gas tube giving you options to mount lights and optics. The handguard on this model is Magpul with M-Lok compatibility along with a comfortable Magpul MOE AK grip.