The CMMG RESOLUTE MK4 in .350 Legend is built on the adaptable Mk4 AR15 platform. It features a 16.1-inch barrel and includes a CMMG 10-round magazine.Key FeaturesIncluded Magazines: Ships with a CMMG 10-round magazine.Action: Operates as a semi-automatic rifle.Rate of Twist: Features a 1:7.50 twist rate.Safety: Equipped with a CMMG Zeroed 60/90 degree ambidextrous safety.