12.5″ Criterion Core Midlength Gas 5.56 Barreled Upper – Sol Test Upper 1

12.5″ Criterion Core Midlength Gas 5.56 Barreled Upper – Sol Test Upper 1

An upper built to test and approve 12.5″ Midlength Gas Criterion Core barrels.

These uppers have been shot and test-fired for 150 rounds, both suppressed and unsuppressed.

Final assembly required; no forward assist or ejection port cover installed.

Specifications

• Caliber: 5.56mm
• Color: Black/Geissele DDC
• Upper Receiver: RDM4 Forged, Milspec
• BCG: None
• Rail: 10.75″ Geissele MK16
• Barrel: 12.5″ Criterion Core, 1:8 Twist, Chrome-Lined
• Gas System: Midlength
• Gas Block: Low Profile BCM
• Charging Handle: None
• Muzzle Device: Surefire SOCOM Closed-Tine Flash Hider, 1/2×28