Geissele Automatics Super Duty SD-556 MOD 1 5.56 NATO AR-15, 14.5 in Pinned & Welded (16+ in OAL), Mid-Length, Free-Float M-LOK
This Geissele Automatics Super Duty SD-556 MOD 1 stands out for its duty-grade build and thoughtful feature set. The 14.5 inch barrel has been pin & welded, bringing overall length to 16+ inches with a closed-tine flash hider. It pairs a cold hammer forged, chrome-lined barrel with a mid-length gas system and ambidextrous controls, and comes in excellent condition with a clean, mirror-finish bore.
Condition
Overall Condition: Excellent condition, showing only faint signs of any prior use or handling.
Bore Overall Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Details: The rifle shows little evidence of prior use or handling. The bore is clean and shiny.
What's Included
- Geissele factory cardboard box with SD-556 MOD 1 label
- 1x 30-round Magpul PMAG GEN M3 (polymer) magazine
The SD-556 MOD 1 is built on the AR-15 platform with Geissele’s Super Duty series features. The 14.5 inch cold hammer forged, chrome-lined barrel is permanently pinned and welded to a closed-tine flash hider for a legal 16+ inch overall length. The case label confirms the 14.5 inch pinned and welded configuration in BLK and matches the receiver serial.
The rifle uses a semi-automatic, direct impingement system with a mid-length gas setup. Barrel specs include a 1:7 twist and 1/2x28 threads beneath the pinned muzzle device, supporting common 5.56 NATO loads and accessories where applicable.
A 13.5 inch free-float aluminum M-LOK handguard provides accessory mounting and a continuous T-marked Picatinny top rail. QD sling attachment is supported via M-LOK QD mounts. The rifle ships with no sights, allowing the user to configure as desired.
Controls and furniture are well-appointed: an ambidextrous safety selector and an ambidextrous charging handle with enlarged bilateral latches enhance handling. The B5 Systems Bravo collapsible stock and 7075-T6 aluminum receivers with a Type III hardcoat anodized black finish round out a durable, USA-made package.