"The first product in this new program is the Daniel Defense MK12 Alpine Predator rifle build. The MK 12 is named after the classic military rifle of the same name, the Mk.12 SPR (Special Purpose Receiver). The Mk.12 SPR was a result of military armorers rebuilding and retrofitting existing receivers and parts with new match-grade 18-inch barrels designed to shoot the famous Black Hills Mk 262 77-grain 5.56 NATO cartridge. These barrels also Ops Inc. Muzzle Brake and collar which allowed for the Allen Engineering 12th Model Suppressor to be directly mounted. SOF units put the Mk.12 SPR to good use during the GWOT era as it provided them with further effective ranges as compared to standard 5.56 NATO M4 and M16s."