Ok got my new rifle in from Surplus ammo and they said lower receiver is a dpms parts kit. so the issue I am having is my 30 round mags catch and lock in nice no problems but my 20 round master molder plastic mags only catch when empty and pushed in hard "I know not good" so is it mags are incompatible? or should I screw in the mag catch lever more or screw out more at moment it is screwed in 3 turns into the screw side. Other than that small issue I would say it is a great rifle for $619 including the free shipping and blackhawk case and 3 3 round pmags hope it fires as nice as she looks. oh yeah and they threw a moe forward on also.