Sharps Bros JACK9 Lower Receiver with Skull Magwell (CAL: MULTI)
Sharps Bros MFG JACK9 AR-style lower receiver featuring the sculpted skull magwell design. Receiver is marked “MDL: JACK9” and “CAL: MULTI” and is identified as 7075-T6 aluminum.
This unit is configured with a receiver extension and a pistol stabilizing brace installed, and includes the fixed ejector commonly found on pistol-caliber lower setups.