Mar 21, 2019 · Combining the DNA of FN’s MK 17 and MK 20 SSR service rifles, the 7.62x51mm (.308 Win.)SCAR 20S is the civilian and law enforcement solution for accurate long range shooting. Every part of the SCAR 20S is designed allow you to hit targets out to 800 yards with ease, from the gas-piston action to the crisp 2 stage match grade trigger. Iron Horse Outfitters | FN America FN America Barrel, 14.5", Hammer Forged, For AR Rifles, Carbine Length Gas System, Black System 36420 Learn More. Fn Bbl Assembly Scar 16s 10" $999.00. Out of stock. FN America Barrel Assembly, 223Rem/556NATO, 10", 1:7 Twist, Fits SCAR 16S, Front Sight Assembly, Gas Block/ Regulator, Gas Piston, and Flash Hider 98802 Learn More.