Geissele Super Duty MOD1 .300 BLK 8" 1:7" CHF Chrome Lined Bbl Black Complete Upper Receiver Group 08-553B

Geissele Super Duty MOD1 .300 BLK 8" 1:7" CHF Chrome Lined Bbl Black Complete Upper Receiver Group 08-553B is built for suppressed, close-quarters work. It runs Geissele's Phased Array gas system on an 8" cold hammer forged barrel.

The 1:7 twist handles both subsonic and supersonic 300 Blackout loads from the same barrel — no swapping needed depending on ammo choice. Chrome lining adds corrosion resistance and extends barrel life under high round counts.

A 7" MK16 Super Modular Rail gives a rigid, lightweight M-LOK platform up front. Round out the package: a Geissele Airborne Charging Handle, a low-profile pinned gas block, and a HUXWRX Flash Hider-QD 762 for suppressor use.

Key Features:

• 8" cold hammer forged, chrome-lined barrel, 1:7 twist
• Geissele Phased Array gas system
• HUXWRX Flash Hider-QD 762, suppressor-ready
• Low-profile pinned gas block
• 7" MK16 Super Modular Rail, M-LOK
• Geissele Airborne Charging Handle
• Black finish
• Ready to mount on any mil-spec AR-15 lower

Complete and suppressor-ready out of the box — this upper's built specifically around what 300 Blackout does best.