The LWRC IC-9K 9mm SBR is the shortest-barreled version of LWRCI’s IC-9 pistol caliber AR, finished in black and built with a barrel just under 6 inches long (LWRCI part no. ICR9B5KS). Rather than a straight blowback bolt, the IC-9 series uses LWRCI’s chamber ring delayed blowback system, in which annular grooves machined into the chamber walls let the expanding case slow the carrier’s rearward travel. The lower is designed around US-manufactured Glock magazines, and this configuration ships with one 27-round magazine. LWRCI’s MonoForge upper receiver carries an integrated rail base and is lighter and stronger than a standard pattern upper. Fully ambidextrous controls, an oversized trigger guard and the LWRCI Ultra Combat Grip make it a compact, easy-handling 9mm for home defense and close-range training.

Key Specifications

• The chambering is 9mm Luger (9x19mm), the pistol cartridge the whole IC-9 family is built around.
• Barrel length is just under 6 inches, the shortest barrel offered across the IC-9 line.
• Rifling is a 1:10 right-hand twist, a standard rate for stabilizing common 9mm bullet weights.
• The muzzle is threaded 1/2×28 TPI, the common pitch for 9mm suppressors and muzzle devices.
• The action is chamber ring delayed blowback, which uses grooves in the chamber to slow the carrier instead of relying on bolt mass alone.
• It ships with one 27-round magazine and feeds from Glock-pattern 9mm magazines.
• The upper is LWRCI’s MonoForge upper receiver with an integrated rail base, lighter and stronger than standard pattern uppers.
• The trigger is the LWRCI Enhanced Fire Control Group, nickel Teflon coated for a smooth, crisp pull with positive reset.
• Controls are fully ambidextrous, covering the fire/safety selector, bolt catch release, magazine release and charging handle.
• An oversized LWRCI Enhanced Trigger Guard leaves room to work the trigger with gloved hands.

Frequently Asked Questions

Which magazines does the IC-9K use? It is built around Glock-pattern 9mm magazines and ships with one 27-round magazine. LWRCI recommends factory Glock magazines for the best reliability, since some aftermarket magazines use weaker springs or loose-fitting followers.

What ammunition does LWRCI recommend? Factory-loaded 9mm that meets SAAMI, NATO or CIP standards. LWRCI function tests the IC-9 series with Remington 147-grain JHP, Winchester 115-grain FMJ and Federal 124-grain +P JHP, and it does not guarantee performance with reloaded, hand loaded or surplus ammunition.

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 IC-9K 9mm SBR, Black, 27-Round Magazine

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 rifle lineup and our Lubbock, Texas team will handle the transfer.