The LWRC ICMKII 10.5-inch SBR is the shortest configuration of LWRCI’s MKII Individual Carbine, chambered in 5.56 NATO and finished in black (LWRC part no. ICMKIIR5B10S). It runs the company’s patented short-stroke gas piston, which LWRCI says delivers reliability in extreme conditions and is easy to maintain. The MKII update brought a redesigned Monoforge upper, an M-LOK handguard and a paddle-style two-position gas block moved inside the rail. Collapsed, the rifle measures 26.5 inches, which makes it a handy host for a suppressor. It is the pick when the shortest piston ICMKII is the goal.

Key Specifications

• Chambering is 5.56 NATO, a widely available cartridge.
• Barrel length is 10.5 inches, the shortest of the ICMKII’s barrel options.
• Overall length is 26.5 to 29.8 inches, depending on stock position.
• The barrel is cold hammer forged with a 1:7 right-hand twist, a rate that stabilizes a wide range of bullet types.
• The heavy-profile barrel is Black Nitride treated and torqued at the factory to a consistent setting.
• Muzzle threads are 1/2×28 TPI, ready for a 5.56 muzzle device or suppressor.
• The operating system is a short-stroke gas piston, which keeps carbon out of the receiver.
• The paddle-style two-position gas block sits inside the rail to switch between suppressed and unsuppressed fire.
• The upper is a Monoforge one-piece receiver with an integrated rail base, coined in the die for precise dimensions.
• Sights are LWRC Flip-Up Skirmish sights, adjustable back-ups that stay out of the way of an optic.

Frequently Asked Questions

What does the MKII change from the original IC? LWRCI redesigned the upper receiver, adopted an M-LOK handguard, and moved a paddle-style two-position gas block inside the rail.

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.

What magazine comes with it? LWRCI ships the ICMKII with a Magpul 5.56 PMAG 30.

Buy the LWRC ICMKII 5.56 SBR, 10.5-Inch Barrel, Black

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.