A Stag AR15 Stripped Lower Receiver is the only way to start your AR15 build. Made to Mil-Spec standards, Stag stripped lower receivers are second to none in quality and works with Mil-Spec AR15 parts & components. Stag is co co-production with Aero Machine 
Stag 15 multi cal is $120/ tax,  Stag 10 mukti cal is 200/ tax