Shield Arms SA-9 Gen 2 9mm Stripped Folding Lower Receiver

The Shield Arms SA-9 Gen 2 is a stripped lower receiver for building a 9mm that runs on Glock double stack magazines. It is machined from billet aluminum and finished in black, and its patented folding mechanism is built into the lower itself rather than added on as an adapter or hinge. That keeps the fold strong and the bulk down, and folding cuts overall length by roughly 8 to 10 inches for storage or transport.

Magazine compatibility covers Glock double stack 9mm magazines, including G17, G19, G34 and aftermarket extended magazines. Last round bolt hold open is integrated, so the bolt locks back on an empty magazine the way an AR shooter expects. The lower is built around the Shield Arms proprietary buffer system, a 7.0 oz stainless steel buffer with a configurable steel weight for tuning, and the buffer retaining pin is threaded for secure retention. Shield Arms also designed the Gen 2 for improved parts compatibility. As a stripped receiver, it is the starting point for a compact, foldable 9mm build.