Geissele Super Duty SD-556 Custom AR Pistol, 300 AAC Blackout, 10.5 in Type A Barrel, DDC Anodized, Ambi Controls, 2 PMAGs
This custom-built AR pistol is assembled on a Geissele Super Duty SD-556 receiver set and chambered in 300 AAC Blackout. It features a 10.5-inch Type A barrel, Type A L119A1 free-float handguard, and Geissele DDC anodized finish across the upper, lower, and pistol receiver extension. Ambidextrous controls, a flat-faced trigger, and quality components throughout make this a well-specified 300 BLK pistol with clean build details.
Condition
Overall Condition: Very good condition, showing only light, superficial signs of prior handling or use.
Specific Condition Details: There are some mild to moderate scuffs and wear in spots.
Bore Overall Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
What’s Included
- Custom Geissele Super Duty SD-556 AR pistol in 300 AAC Blackout (as described)
- 2x 30-round Magpul PMAG 300 BLK polymer magazines (marked "300" in paint pen)
- Knurled thread protector (installed)
- Ladder-style rail covers installed on handguard
This build centers on a Geissele Super Duty SD-556 receiver set with a Geissele buffer assembly and Geissele Maritime bolt catch, finished in the factory DDC anodized (gold/bronze). It is configured as an AR pistol with a smooth pistol receiver extension and no stock or brace. Capacity is 30+1.
The upper is outfitted with a Type A 10.5-inch 300 BLK barrel and a Type A bolt carrier group. A flat-faced Type A trigger and Type A lower kit round out the fire control group. The action is semi-automatic, direct impingement, with a standard right-side magazine release, ambidextrous safety selector, and ambidextrous charging handle for versatile handling.
The Type A L119A1 free-float aluminum handguard provides a full-length T-marked Picatinny top rail, M-LOK slots at 3, 6, and 9 o’clock, and short front Picatinny sections for accessories. Ladder-style rail covers are installed for added grip and protection. The muzzle is threaded and fitted with a knurled thread protector.
Receiver markings include "GEISSELE AUTOMATICS" with model "Super Duty SD-556," and the right side marked "GEISSELE AUTOMATICS - NORTH WALES, PA" with SAFE/FIRE selector markings. The lower is rollmarked "CAL 5.56MM," while this build is chambered in 300 AAC Blackout per the barrel and included magazines. The pistol wears a Magpul MOE-K2 grip and is finished to match in Geissele DDC anodizing across the upper, lower, and receiver extension.