Geissele Super Duty SD-556 Mod 1 5.56 NATO AR-15 Rifle, Pinned & Welded 3-Prong, Free-Float M-LOK, Ambi Controls
This Geissele Automatics SD-556 Mod 1 from the Super Duty series is a factory-built 5.56 NATO AR-15 configured with ambidextrous controls, a free-float M-LOK handguard, and a flat-faced trigger. It features a closed-tine 3-prong flash hider that is pinned and welded, and comes in as-new condition with its factory box and serial-matched label confirming the Mod 1 14.5-inch P&W configuration. Made in the USA, it combines premium components with clean execution throughout.
Condition
Overall Condition: As-new condition with no signs of prior handling beyond what’s typical from inspection (see photos).
Specific Condition Notes: This rifle is in pristine shape with minimal evidence of wear or use.
Bore Overall Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
What’s Included
- Factory Geissele Super Duty cardboard box with serial-matched label (SD-556 MOD 1, 14.5" P&W)
- One 30-round Magpul PMAG polymer magazine
Factory details confirm this is the Super Duty SD-556 Mod 1, with the carton label specifying "Super Duty Rifle Mod 1, 14.5 inch, P&W – BLK" and matching the rifle’s serial. The receiver is marked "GEISSELE AUTOMATICS, NORTH WALES, PA, U.S.A." and has SAFE/FIRE selector markings on both sides, reflecting its ambidextrous setup.
The rifle uses a free-float aluminum M-LOK handguard with a continuous, T-marked Picatinny top rail and integral QD sling cups for straightforward accessory and sling placement. The barrel is threaded and capped with a closed-tine 3-prong flash hider that is pinned and welded, delivering a durable, compliance-ready muzzle setup from the factory.
Controls are fully ambidextrous with a safety selector and paddle-style magazine release. The fire control group features a flat-faced trigger. A Geissele-marked bolt carrier is present, with a standard, unmarked forward assist and plain ejection-port cover, and the STANAG-pattern magazine interface provides a stated capacity of 30+1 rounds.
Furniture includes a B5 Systems adjustable carbine stock and a Geissele-marked polymer pistol grip. The rifle is finished in black with aluminum receivers, and has a listed length of pull of 11.25 inches for a compact, adjustable fit.