Im getting into some high power rifle shooting comps. My tjiughtsnare, I'd like to build both an ar replica upper, and an a2 irons setup. I was in durring the transition of use between the 2, and for nostalgic reasons only I'd like to setup as I was issued. So my main question is, are people using the fn uppers for the collector series? Or are you running something else? I'm not looking for better parts, cheapest parts, etc... depending on the divison, you cant run accurized equipment anyways. They're both basically just HB profile 20 inch, thoughts appreciated