11.5″ Colt Heavy FBI/HRT MK4 Federal – ODG

-11.5″ Colt 5.56 heavy barrel, 1/7 twist, chrome lined bore and chamber, 1/2-28

-Colt M4 cage code upper

-Geissele MK4 Federal 10″ rail ODG

-Geissele super gas block pinned

-PRI carbine length gas tube