The Colt ERP, or Enhanced Patrol Rifle, line of M4 Upper Receivers that come with Centurion Arms free float M-LOK handguards, making for a convenient and practical upper receiver ready to drop on your AR-15 lower receiver. Available in 3 different barrel lengths, each is chrome lined, has a 1-7 twist, is button rifled, and has a phosphate finish. You can also choose between complete, which includes a M16 bolt carrier group and charging handle or stripped which does not include those items. All NFA rules apply. Mfg: Colt
