Geissele Automatics SD-556 Super Duty 5.56 NATO AR-15, 16.1 Inch, Geissele Flat-Bow Trigger, Ambidextrous Controls, Pinned & Welded
The Geissele Automatics SD-556 Super Duty is a 5.56 NATO AR-15 built on a forged-profile receiver set with ambidextrous controls and Geissele’s flat-bow trigger. It features a free-float aluminum M-LOK handguard with a T-marked, full-length Picatinny top rail, a 16.1-inch barrel with a multi-prong flash hider, and a B5 Systems adjustable carbine stock. This example is in excellent condition and comes with a Magpul PMAG and installed textured M-LOK rail covers.
Condition
Overall Condition: Excellent condition, showing only faint signs of any prior use or handling.
Bore Overall Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: There are minimal markings from previous handling and use. Please refer to the photos for close-ups and additional views.
What’s Included
- 1x 30-round Magpul PMAG polymer AR-15 magazine
- Textured M-LOK rail covers installed on the handguard
The lower receiver is marked "GEISSELE AUTOMATICS" with the keystone "SUPER DUTY," model "SD-556" and "CAL 5.56MM." The right side carries "GEISSELE AUTOMATICS, NORTH WALES, PA" with SAFE/FIRE selector legends. The forged-profile AR-15 receiver set includes a forward assist and an ejection-port dust cover, and the rifle wears a hard-anodized black finish.
Ambidextrous controls are extensive: an ambidextrous safety and an ambidextrous charging handle with an extended latch are present. An enlarged left-side bolt catch is paired with a right-side bolt catch/release lever above the magazine release for efficient manipulation. A Geissele-marked bolt carrier is visible through the ejection port.
The fire control group features a Geissele flat-bow trigger. The 16.1-inch barrel is capped with a multi-prong flash hider, and the muzzle device is pinned & welded. Operation is semi-automatic with a direct-impingement gas system.
The free-float aluminum handguard provides elongated M-LOK slots and a T-marked, full-length Picatinny top rail. Textured M-LOK rail covers are installed. Furniture includes a B5 Systems adjustable carbine stock and a textured polymer pistol grip; length of pull measures 14.75 inches.
No sights are installed from the factory on this example. Capacity is 30+1 with the included Magpul PMAG.