Often times a shooter is looking for a shorter barrel, and wonders if the Mk18 style 10.3" or the M4A1 length of 14.5" is best. Both have their places, but the 11.5" barrel presents a sweet spot that is more forgiving than the 10.3", and is shorter and more manuverable than the 14.5". The 11.5" barrel is a great choice for a short barreled rifle or even a pistol configuration.
Daniel Defense barrels are known as some of the best made and most accurate barrels in the shorter barrel lengths. The DD 11.5" is a government profile, and is made from chrome-moly-vanidium 4150 steel alloy and is cold hammer forged, to produce an accurate and consistent barrel. The barrel is chambered in 5.56 NATO with a 1:7 twist and chrome lined for extended durability and corrosion resistance. Like all military correct barrels, the DD 11.5" is phosphate coated and comes with a carbine length gas system.
This barrel comes with a DD low-profile gas block pinned to the barrel. With a short, but heavy hit of a larger pin punch, the taper pin will fall out, and the gas block will slide off. You then can install the barrel nut of your choice and reinstall the gas block with the taper pin. Charlie's chief armorer recommends a dab of red Loctite to help seal the block, but that is optional.
The low profile gas block enables you to install any variety of free floating hand rails. Perfect for a Daniel Defense R-III, or RIS-II, or choose any popular brand, like Geissele or Midwest Industries, for instance.
NFA disclaimer: If assembled as a rifle, the rifle will most likely be a Short Barreled Rifle, and subject to NFA restrictions. Please educate youself on NFA laws.