I am planning to either build or buy a 20" standard conf. A3 rifle for target shooting.  I want to get either an all RRA or all Bushmaster gun. I called Sales at Bushmaster and asked about parts kits. In talking, the salesperson told me you don't save any money in assembling a Bushmaster as opposed to buying one. Is this correct? Also, do you save getting a Rock River gun instead of a Bushmaster? (I am making the assumption the quality is the same.)And what does ".223 Wylde" mean? Thanks for any replies.