Centurion Arms C4 20-inch Rifle with Criterion Core Barrel

A 20-inch rifle on a Centurion Arms C4 receiver set and 12-inch C4 rail, with a Criterion Core chrome-lined barrel and a BCM fixed front sight base. It runs a LaRue MBT-2S, a VLTOR A5 buffer system and a Magpul UBR stock, with a Driven Arms Shadow Crossover grip and Breek Warhammer charging handle. The builder is waiting on a Primary Arms PLxC 1-8 to finish it.