Geissele Super Duty SD-556 5.56 NATO, 16 inch AR-15 with MK16-Pattern M-LOK Handguard, Ambi Controls, and Pinned & Welded 3-Prong
This Geissele Automatics Super Duty SD-556 stands out with its factory ambidextrous controls, Geissele-marked bolt carrier, and MK16-pattern free-float handguard. It features the Geissele Airborne Charging Handle (PN 05-497) and a 3-prong flash hider that is pinned and welded. The lower is SD-556 marked with the Keystone logo, and the rifle is finished in black anodized aluminum with a 16 inch 5.56 NATO barrel.
Condition
Overall Condition: Very good condition, showing only light, superficial signs of prior handling or use.
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: There are a few scuffs on the Picatinny rail and near the magwell, but the rifle is otherwise in great shape.
What's Included
- 1x 30rd Magpul PMAG GEN M3 polymer magazine
The SD-556 configuration pairs a 16 inch 5.56 NATO barrel with a free-float MK16-pattern aluminum handguard that uses a two-bolt clamp and a center indexing tab. The handguard carries a full-length 1913 top rail and M-LOK slots for direct accessory attachment along its 15.0 inch length.
Controls are fully ambidextrous where specified. It has an ambidextrous safety, an ambidextrous paddle-style textured magazine release, and an enlarged maritime-style bolt catch for positive manipulation. The charging system is Geissele’s Airborne Charging Handle (PN 05-497) with ambidextrous latches.
The operating system is semi-automatic, direct impingement. A Geissele-marked bolt carrier is included, and the flat-bow trigger provides a straight-face geometry. The threaded barrel is topped with a 3-prong flash hider that is pinned and welded, securing the muzzle device in place.
The rifle uses aluminum receivers with a black anodized finish and a black adjustable polymer stock. It includes a textured pistol grip and a 13.0 inch length of pull. Capacity is 30+1, and the country of origin is the USA. The lower receiver is SD-556 marked with the Keystone logo.