Geissele Automatics SD-556 Super Duty 5.56 NATO 16 in Rifle, MK16 15 in Rail, SSA-E X Trigger, Nanoweapon BCG - Black
This Geissele SD-556 Super Duty stands out with a Super Mid-Length gas system, a Reliability Enhanced BCG with Nanoweapon coating and Carpenter 158+ "Stressproof" bolt, and the SSA-E X two-stage Lightning Bow trigger set at 3.5 lb. It pairs a 16 in cold hammer forged, chrome-lined barrel with a 15 in Super Modular Rail MK16, all on 7075-T6 forged receivers finished in Type III hardcoat anodizing. Excellent overall and bore condition round out a feature-rich, US-made AR-15 platform rifle.
The rifle features a Geissele Airborne Charging Handle (ambidextrous) with low-profile latches, an ambidextrous safety, and a Geissele Maritime bolt catch. The MK16 rail includes anti-rotation tabs, integral QD sockets, and a full-length T-marked top rail. A Geissele 4-prong flash hider sits on the threaded muzzle. An adjustable stock with QD socket and a B5 Systems pistol grip complete the setup.
Condition
Overall Condition: Excellent condition, showing only faint signs of any prior use or handling.
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Rifling: Excellent - Sharp lands and grooves.
Specific Condition Notes: There is minimal evidence of prior handling or use.
What's Included
- Geissele Automatics SD-556 Super Duty 5.56 NATO rifle
- One 30-round Lancer L5AWM polymer magazine
The operating system is semi-automatic, direct impingement with a Super Mid-Length gas system designed for smooth cycling. Geissele's Reliability Enhanced BCG uses a Nanoweapon coating and a Carpenter 158+ "Stressproof" bolt for durability and ease of maintenance. The Geissele Maritime bolt catch and ambidextrous safety enhance handling and control.
The 16 in cold hammer forged, chrome-lined barrel features a 1:7 twist and a threaded muzzle fitted with a Geissele 4-prong flash hider. This barrel specification supports a wide range of 5.56mm bullet weights and emphasizes longevity and consistent performance.
The Super Modular Rail MK16 measures 15.0 in and includes anti-rotation tabs, integral QD sockets, and a T-marked full-length top rail for mounting. The rifle includes a scope-mounting provision via the continuous top rail.
Controls and ergonomics are thoughtfully executed: the Geissele Airborne Charging Handle (PN 05-497) is ambidextrous with low-profile latches, and the trigger is the Geissele SSA-E X two-stage Lightning Bow with a flat face and a 3.5 lb pull. The stock is adjustable with a QD socket, paired with a B5 Systems pistol grip; length of pull is 13.5 in.
The upper and lower receivers are 7075-T6 forged aluminum with a Type III hardcoat anodized black finish. This rifle is made in the United States and ships with a 30-round Lancer L5AWM magazine for a 30+1 total capacity.