I’m not sure about that - I can get most of them to shoot inside a dime at 100 yards with the right accurizing.
I think you will be disappointed.
Expecting that accuracy from that type AR just isn't going to happen with a human behind the rifle.
Having said that, the most accurate barrel would be a high end custom with a tight match chamber and properly headspaced bolt. Why do you need a .5 MOA SBR???
