Heckler & Koch MR556 A4 Pistol, 5.56 NATO, 11-inch CHF Barrel, Short-Stroke Piston, Earth-brown, Ambidextrous Controls
This recent-production HK MR556 A4 Pistol stands out with its short-stroke gas piston system, 11-inch cold hammer-forged barrel, and earth-brown finish. It features fully ambidextrous controls, a slim free-float M-LOK handguard with QD sockets, and a full-length T-marked Picatinny top rail. As-new condition, an HK shield CF date code, and a Columbus, GA import mark add to its appeal. Included are a Pelican Storm iM3100 hard case and one 30-round PMAG.
Condition
Overall Condition: As-new condition with no signs of prior handling beyond what’s typical from inspection (see photos).
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: This example presents in phenomenal shape and appears almost unused.
What’s Included
- Pelican Storm iM3100 hard case
- One 30-round Magpul PMAG GEN M3 5.56x45 magazine
The MR556 A4 Pistol uses HK’s semi-automatic, short-stroke gas piston action with a 2-position adjustable regulator marked N/S. The 11-inch cold hammer-forged steel barrel is free-floated, cut with a 1:7 RH twist, and threaded 1/2x28 with a birdcage flash suppressor.
Controls are fully ambidextrous, including the magazine release, bolt catch/release, and a 45-degree safety selector. An ambidextrous charging handle with bilateral latches and a tensioning buffer that improves receiver fit round out the handling features.
The slim free-float aluminum M-LOK handguard integrates QD sling sockets and a full-length T-marked Picatinny top rail. An HK MR-marked ejection-port cover and an HK 416-style textured polymer grip are installed.
The aluminum receiver set wears an earth-brown finish, matched to the frame. An SB Tactical pistol brace is installed. Markings include Heckler & Koch Inc., Columbus, GA (import) and the HK shield CF date code. Capacity is 30+1.