Core15 Hardcore System X4
5.56 NATO or 6.5 Grendel (new 2016) cal., GIO, 18 or 20 (new 2016) in. fluted black Nitride finished or stainless steel (new 2016, 20 in. only) barrel, rifle length gas system, low profile gas block, Lantac Dragon muzzle brake, Magpul Gen M...