Re: Recommendations for bbl break in on my new AR
A) Go to the range, with the rifle.
B) Load the rifle.
C) Shoot the rifle.
D) When you're done, clean the rifle. But don't get crazy about it.
Keep it properly lubed (which again, means don't get crazy about it), and it'll run just fine. You're dealing with a chrome lined bore that was never intended for match accuracy, in a rifle that's not set up to deliver match accuracy. You're worrying way too much about this. Just have fun with it.
And yes, you'll need to break the rifle down ("shotgun" it)) to insert a bore guide. Never clean from the muzzle, ALWAYS from the chamber.