Polymer......have no personal experience but look at the price. Would be good for a 22 build. I've heard good and bad stories about polymer in this platform.
E3 Arms AR-15 Improved Gen II Complete Polymer Lower Receiver
E3 Arms AR-15 Improved Gen II Complete Lower Receiver model C15 w/ commercial buffer tube and slider - Black This updated E3 Arms complete lower receiver features an improved ergonomic grip with trap door and a tactical buttstock with a quick detach sling swivel attachment port... ( Sling Swivel...
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