Geissele Super Duty SD-556 AR Pistol, 12.5" Ballistic Advantage Barrel, DDC, Custom Ambi Controls, 5.56 NATO
This custom-built Super Duty SD-556 pairs Geissele’s forged Desert Dirt Color receiver set with a 12.5-inch Ballistic Advantage nitrided barrel and a suite of premium ambidextrous controls. Lightweight internal parts, a Q Cherry Bomb muzzle device, and an SB Tactical SBA5 brace create a compact, fast-handling platform chambered in 5.56 NATO.
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 - Sharp lands and grooves.
Specific Condition Notes: Mild finish wear is visible on a few high-contact edges, and light carbon buildup is present around the gas block and muzzle device.
What’s Included
- Geissele Super Duty SD-556 AR pistol configured as described
- 1x 30-round Magpul PMAG polymer magazine
The heart of this build is a Geissele forged SD-556 receiver set finished in matching Desert Dirt Color Cerakote. The upper sports a continuous, numbered 1913 rail and Geissele’s Maritime ambidextrous bolt catch for intuitive control from either side.
A 12.5" Ballistic Advantage nitrided barrel is secured under a free-floating Geissele Super Modular Rail MK16. The M-LOK handguard is torque-spec laser-etched from the factory and keeps weight down while providing ample accessory space.
Recoil impulse is softened by a KAK Industry lightweight 7075-T6 bolt carrier group and a Q Cherry Bomb muzzle device that doubles as a fast-attach suppressor adapter. The barrel’s 1/2-28 threads leave room for other muzzle options if desired.
Controls are fully ambidextrous: Aero Precision Breach Mod 4 charging handle, flared magazine release button, and an ambi safety selector. Geissele’s two-stage trigger breaks clean, supporting accurate shooting from the compact 12.5-inch platform.
An SB Tactical SBA5 adjustable arm brace and B5 Systems Type-23 pistol grip finish the lower, offering a stable, ergonomic interface in flat dark earth to match the DDC receivers.