hey guys i wana build a mid range rifle. i would love to be able to reach out as far as possible (maybe 300-800 yds) and realise it takes skill to go out farther and would like to learn these skills. i was thinking to build a ar 10 or a ar 15 varient maybe a 6.5 or 762 im new to all these rounds and dont really know how far each can reach. i wouldnt mind buying a semi auto rifle. My price range for buying a rifle would be around 700$ i know that probably leaves me around a bolt action but what all do you reccomend im looking for something very accurate. if i build this rifle i can spend more over time more then the 700$ whats advantage of 6.5 or 308?? how far can a 556 go out of a 18 or 20 in barrel ive always wanted a SCAR should i just save the money?