Daniel Defense M4A1 SOCOM Block II Stripped Upper 14.5"

The Daniel Defense M4A1 SOCOM Block II Upper Receiver is the Block 2 host that carries the SOCOM heavy barrel profile, the medium-heavy contour SOCOM adopted for the M4A1 to handle volume of fire. Three contour names get muddled here, and only one of them is a genuinely different barrel. Daniel Defense's own factory M4A1 rifle ships the M4 profile, which is the government profile with the M203 cut machined in; the URG-I upper USASOC fields runs that same government contour on mid-length gas. This upper is the outlier: the heavier SOCOM profile on carbine gas, the contour SOCOM adopted to handle volume of fire. The 14.5-inch barrel is cold hammer forged from chrome-moly vanadium, chrome lined, 1:7 twist, fed by a carbine-length gas system under a pinned low-profile gas block and the RIS II Picatinny quad rail SOCOM adopted in 2005.

This upper ships stripped: it does not include a bolt carrier group, charging handle, or muzzle device. That is a feature for a strict clone, not a drawback. The bare 14.5-inch 1/2x28 muzzle lets you pin and weld the correct SureFire SOCOM device (the SF3P or Warcomp the SOCOM RC2 fast-attaches to) to reach 16 inches, so unlike the complete RIS II rifle this is a drop-in path to a suppressor-correct front end. Add a Daniel Defense or BCM M16-profile BCG and an ambidextrous charging handle to complete it.

Plan for the extra parts and the pinning when you budget this host. In exchange you get the only Block 2 upper with the correct heavy barrel profile and a muzzle you can spec yourself, which is why it is the purist's choice over the FSP URG and the complete RIS II rifle.