I am thinking about building a upper and then later on a lower. This upper will be swapped on and off my recent DPMS AR purchase. That is until I eventually get a lower to go with it. But would like all the input I can get from you guys on here that use AR's. So I want the upper capable of 300 yard accuracy. Thats about the furthest I could use it here around me. But I feel if it is accurate at 2-300 yards then it will be more so at 100. I'm hoping to build a accurate budget build that want break the bank but shoot very good. 1. Anderson Manufacturing AR A3 Stripped Upper Receiver $39.95 Click Here Would like to go with a AR15P barrel and wondering if the 5/8x24 is the better barrel than the 1/2x28 or if it will make that much of a difference. Would the listed 16" barrels do the job or do I need to go with a 18" or even a 20"? 2. 16" 5.56 3R Socom barrel, 4150 CMV, Wylde chamber 5/8" $185.00 Click here OR 2A. 16" 5.56 3R Scout barrel, Wylde chamber 1/2-28 Click Here Not sure of a handguard yet, so through some ideals out there.