hi im new here but not new to ar-15's, but new to the ar 308 platform i read on another post here that a dpms barrel will work with a armalite receiver as long as the bolt carrier is a dpms as well. i am starting to build my first 308 ar and havent really started building anything just really messing with the new parts that came in. i have a dpms barrel and a dpms bcg but i am using an armalite receiver. my question is when i attach the barrel to the receiver and insert the bcg and charging handle, i have to push the charging handle and bcg some what hard and when the charging handle and bcg are flush in the rear of the receiver, the bolt twists from the bcg being pushed forward. is that normal? thanks