The LWRC ICMKII 14.7-inch Patriot Brown SBR is a 5.56 NATO short-barreled rifle with LWRCI’s longest short-barrel option (LWRC part no. ICMKIIR5PBC14S). LWRCI builds it on its patented short-stroke gas piston system with a one-piece Monoforge upper receiver. The barrel is cold hammer forged, Black Nitride treated and cut with a 1:7 twist that stabilizes a wide range of bullet weights. Patriot Brown sets it apart from the black rifles, and a Magpul PMAG 30, Skirmish back-up iron sights and ambidextrous controls round out the package. It is a distinctive take on the short piston AR.

Key Specifications

• The chambering is 5.56 NATO, for plentiful, affordable ammunition.
• Barrel length is 14.7 inches, the longest of the ICMKII’s short-barrel configurations.
• The barrel is cold hammer forged and Black Nitride treated in a heavy profile with a 1:7 right-hand twist.
• The operating system is LWRCI’s short-stroke gas piston, which the company says is easy to maintain.
• The upper is a Monoforge one-piece forging, struck twice in the die for precise dimensional accuracy.
• The muzzle is threaded 1/2×28 TPI, the common thread for 5.56 muzzle devices.
• The color is Patriot Brown, one of the five finishes LWRCI offers on the ICMKII.

Frequently Asked Questions

What magazine does this ICMKII SBR use? LWRCI supplies a Magpul 5.56 PMAG 30 with the rifle.

Are the controls ambidextrous? Yes. LWRCI says the bolt catch, bolt release, magazine release, safety selector and charging handle are fully ambidextrous.

Do I need ATF approval to buy this? No. As of October 9, 2026, ATF no longer requires Form 4 approval, registration or a tax stamp for short-barreled rifles. It transfers on a Form 4473 with a background check through a Class 3 (SOT) dealer. State and local laws still apply. Taking an SBR across state lines still requires an approved ATF Form 5320.20.

Buy the LWRC ICMKII SBR, 5.56 NATO, 14.7-Inch Barrel, Patriot Brown

As of October 9, 2026, this short-barreled rifle transfers on a Form 4473 with a background check at your Class 3 (SOT) dealer, with no Form 4 or tax stamp; state and local laws still apply. Order through LWRC‘s short-barreled rifles lineup and our Lubbock, Texas team will handle the transfer, and it ships fast to your Class 3 dealer.