L-R .300 Whisper, .223 Rem, .458 SOCOM Rock River Arms AR platform chambered in .458 SOCOM Specs Caliber: .458 SOCOMBarrel: 16” Chrome Moly Bull Barrel, 1:14 R TwistAction: Semi-Auto AR PlatformOverall Length: 36”Weight (empty): 7.6… .458 SOCOM/ RRA LAR-458