Daniel Defense DD4 RIII Upper Receiver Group

The DD4 RIII Upper Receiver Group is Daniel Defense's general-purpose upper under the current DD4 naming. It pairs a 16" Government profile barrel with a mid-length gas system, which is the combination that gives up the least in either direction: enough barrel for full 5.56 velocity, and enough dwell for a softer impulse than a carbine-gas 16".

The barrel is cold hammer forged Chrome Moly Vanadium, chrome lined, and mil-spec heavy phosphate coated, with a 1:7 twist and an HP/MPI test behind it. Gas is taken through a pinned low-profile block CNC machined from 4140 hardened steel. Out front sits the Daniel Defense flash suppressor in salt bath nitrided 17-4 PH stainless.

Everything above the barrel is the RIII system. The 12.5" RIS III M-LOK rail free-floats the barrel and keeps a continuous 1913 top rail, the upper receiver is CNC machined 7075-T6 with indexing marks and M4 feed ramps, the bolt carrier group is the M16 profile unit Daniel Defense ships on every complete URG, and the GRIP-N-RIP ambidextrous charging handle is included. Sights and optics are sold separately, so the only thing between this upper and a complete rifle is a lower.