Radical Defense MK1 Mod 1, CQC, SBR, 5.56 NATO, 12.5″ Barrel, Black, 30 Rounds

The Radical Firearms CQC SBR with 12.5″ barrel is purpose-named for its role: Close Quarters Combat. The 12.5″ barrel length sits between the MK18-standard 10.3″ and the M4-standard 14.5″, providing better gas dwell time and cycling reliability than the shorter MK18 while remaining in the compact SBR category. Military special operations units have evaluated 12.5″ configurations as a compromise between the MK18’s compactness and the M4’s reliability margin — the CQC occupies exactly this position. At $1,299, Radical Firearms makes this configuration available at a price point that positions the NFA Form 4 and stamp as the primary investment rather than the rifle itself.

Radical CQC SBR 12.5″ Specifications

Why Buy From Western Sport?

Western Sport is a licensed FFL/SOT dealer in Roanoke, Texas, specializing in NFA suppressors and SBRs since 2007. We are an authorized Radical Firearms dealer and handle all Form 4 NFA transfers. Our team knows every product in our NFA inventory. Call 817-393-4000.

FAQ — Radical CQC 12.5″ SBR

What is the effective range of a 12.5″ 5.56 SBR?

A 12.5″ 5.56 SBR is most effective at 0–300 yards in practical applications. Muzzle velocity is approximately 2,600–2,800 fps with M855 — sufficient for reliable terminal performance against unarmored targets at 300 yards. This is a close-quarters optimized platform, not a precision rifle, and its range limitations should be understood accordingly.

Recent eForm 4 approvals have been coming back in about two weeks or less — see our NFA wait times guide for current figures.