You\'ll love that the handguard has dual insulated aluminum shielding for noticeably effective heat protection, and the direct gas operating system is uniquely designed to eliminate the conventional operating rod, resulting in fewer and lighter components. It\'s incredibly versatile, as it accommodates the full range of 5.56mm ammunition including the NATO M855/SS109 and U.S. M193, utilizing a rifling twist of 1 turn in 7.Oh, and did we mention that this M4 Carbine is also available with a step-cut barrel that allows it to accept a grenade launcher for recreational, non-lethal options! Check out details in the Manufacturer\'s description, and make sure to check the legality in your area before considering adding this feature to your M4.