Geissele Super Duty SD-556 5.56 NATO AR-15 Rifle, 14.5 in Barrel Pinned/Welded to 16.25 in, Free-Float M-LOK, Ambi Safety, Right-Side Bolt Catch
This factory Geissele Automatics Super Duty SD-556 stands out with its 14.5-inch barrel professionally pinned and welded to a 16.25-inch overall barrel length, a Geissele Airborne Charging Handle, and enhanced controls including a right-side bolt catch/release and ambidextrous safety. It features a free-float M-LOK handguard with a continuous, T-marked 1913 top rail and a factory SD-556 roll-marked receiver with the keystone SUPER DUTY logo. The bore condition is excellent.
Condition
Overall Condition: Good condition, showing some signs of prior use and handling.
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: There are markings from prior handling and use visible on exterior surfaces.
What’s Included
- One 30-round translucent polymer 5.56 magazine marked 'Made in Germany'
- M-LOK QD sling socket (installed on handguard)
- Short M-LOK Picatinny rail section (installed on handguard)
- Picatinny riser segment clamped to the upper receiver rail (installed)
Built on Geissele’s AR-15 platform, the Super Duty SD-556 is a semi-automatic, direct-impingement rifle chambered in 5.56mm NATO with a 30+1 capacity. It is compatible with STANAG-pattern 5.56 magazines and is made in the United States.
The rifle uses a 14.5-inch barrel with a closed-tine (closed-end) flash hider that is pinned and welded to achieve a 16.25-inch legal barrel length. The free-float M-LOK aluminum handguard includes a continuous 1913 Picatinny top rail with T-marks and an anti-rotation interface for secure mounting.
Controls are enhanced with a right-side bolt catch/release in addition to the standard left-side control and an ambidextrous safety. A Geissele Airborne Charging Handle is installed. Furniture includes an adjustable polymer stock and an A2-style AR-15 pistol grip, with a standard magazine release.
The factory SD-556 roll-marked receiver carries the keystone SUPER DUTY logo with Geissele Automatics, North Wales, PA markings. The aluminum receivers are finished in black hardcoat anodizing. The upper’s top rail currently has a Picatinny riser segment installed.