DRD Tactical CDR-15 rifles feature billet receivers, DRD quick detach 13” rail, Magpul CTR stock, MOE grip, and custom cut foam hard case. The CDR-15-300BLK features a melanite coated 16” carbine-length gas system; wheres, the CDR-15-556 features a hammer forged 16” chrome-lined, parkerized, mid-length gas system.