Heckler and Koch MR556 A4 SBR 5.56 NATO .223 Rem 11" Threaded 30+1 81001048

Heckler and Koch MR556 A4 SBR

The Heckler and Koch MR556 A4 SBR is a semi-automatic short barreled rifle chambered in 5.56 NATO and .223 Rem. An 11 inch cold hammer-forged barrel is threaded 1/2x28 and uses a 1:7 twist. The short stroke gas piston system is built to keep fouling out of the receiver and cut wear during hard use. Overall length is 26.5 inches, finish is black anodized, and capacity is 30+1.

An adjustable gas regulator lets the shooter set the rifle for suppressed or unsuppressed fire. The upper follows HK416 lines, the lower is fully ambidextrous, and the safety lever, charging handle, and QD end plate are set up for either-side control. A continuous top rail runs from the receiver onto the M-LOK free float handguard for a solid optic mount. The HK416 slimline stock collapses and folds, and the handguard adds M-LOK slots with integrated ambidextrous QD cups.

This SBR fits duty, training, and compact carbine roles that need a piston-driven 11 inch 5.56 host. The threaded muzzle and adjustable gas system support suppressor use without a separate upper. Shooters who want an MR556 A4 with ambidextrous controls, an M-LOK handguard, and a 30-round magazine will find it built for reliability in a short NFA package. NFA rules apply.

Specifications