I've begun to do some preliminary research for building an ar-15 and have noticed that in .223/5.56 most components are interchangeable but every .308/7.62 component states that any compatibility with another manufacturer is pure coincidence. I would like to do .308 but since arts are significantly less common and not as interchangeable I'm wondering if a .308 would be best store bought and if i should stick to .223 if i want to build. I am more of a handgun guy so this will be my first and probably only rifle and my goal is to buy/build the most accurate piece within my budget.

