BF15 M4 TIER 3
5.56 NATO cal., GIO, 16 1/2 in. M4 barrel with A2 birdcage flash hider, F-Marked A2 front sight post gas block, aluminum flat-top A3 upper receiver with Mil-Spec Picatinny rail system featuring M4 feed ramps, double heat shield M4 handguard...