M4A1 SOPMOD Block 2 Upper Receiver — Military Special | The Most Capable M4 Configuration Ever Fielded
The SOPMOD Block 2 represents the apex of the M4A1's development — the configuration fielded by U.S. Army Special Forces, Rangers, and other tier units in the mid-to-late 2000s through today. This upper is CCC's custom-built interpretation of that configuration: a genuine Colt receiver mated to a Daniel Defense M4A1 RIS-II rail in FDE, a 14.5" SOCOM-profile barrel pinned and welded to a Surefire Warcomp SOCOM extended flash hider for a legal 16" overall length. This is as close to the real thing as a civilian can own.
Understanding SOPMOD Block 2
The SOPMOD (Special Operations Peculiar MODification) kit evolved through two generations. Block 1 was the KAC RAS-railed M4A1 of the late 1990s and early War on Terror. Block 2 replaced the KAC round rail with the Daniel Defense M4A1 RIS-II — a full-length, free-floating quad rail that provided superior attachment points for the full SOPMOD accessory suite: AN/PEQ-15 laser, Surefire M900 or M952 light, suppressor, and optic.
The RIS-II comes in two correct configurations: straight rail (no FSB) and FSP (with front sight base). CCC offers both because both are historically correct — the military transitioned away from FSB on Block 2, but early Block 2 rifles retained the FSB. Charlie's has been building these for collectors and enthusiasts since 2017, and we know which configuration is right for your reference year.
Who This Is For
Serious M4A1 clone builders who want a complete, ready-to-mount upper. Collectors building reference-correct SOPMOD Block 2 configurations. Anyone who wants the complete Block 2 upper without sourcing individual components across multiple vendors — CCC does that for you.
What You Should Know Before Buying
14.5" barrel is pinned and welded to the Surefire Warcomp for a legal 16" non-NFA configuration. Ships as a non-serialized upper; no FFL required. Mates with any mil-spec lower receiver. Contact CCC to confirm current rail configuration (straight vs. FSP) availability.
Complete Your Block 2 Build
→ Geissele Super Duty Stripped Lower
→ KAC NT4 Suppressor (correct Block 2 accessory)
Further Reading
→ The M4A1 Carbine — American Rifleman
→ Daniel Defense Coverage — The Firearm Blog
CCC has been building reference-correct SOPMOD Block 2 configurations since 2017. If you want to talk through your full build — lower, optic, accessories — we're the right shop for that conversation.
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