First AR (Grendel) Build - many questions

[FLshooter]

BCA will replace your barrel if you’re not satisfied after 300 rounds. But by the time you get a barrel that you’re satisfied with,you may have burned $1000 worth of ammo and wasted a ton of time.And then ,there’s the likelihood you will realize that BCA is a waste of time and you may as well buy a quality barrel.
That’s where I’m at.I owned a couple of BCA barrels.Never got the performance out of them that I wanted. So I sold the BCA barrels to a sucker on EBay or wherever I could find one and replaced with a quality barrel.Been happy shooting small groups ever since!