I have an Armalite ar15 I want to dress up up for whitetail. I sold the 458 socom I had, and I want to go with the 6.5 grendel in (probably) a 20 inch barrel. What is the cheapest path to an ACCURATE 6.5 grendel? I'm willing to do some work putting parts together and doing research. I have a friend who is a gunsmith, he helps me when I need it. Thanks.