Select the ammo round that you want based on what you want to do with it. Most that I've talked to about hunting with an AR like to have at least a round that's around 30 Caliber. .223 and 5.56 are too small.
Some choices that fit on the AR frame are 300 Blackout and 6.5 Grendel. There may be a...
New user, recently getting into building AR's. It's a somewhat expensive hobby, so I need to get rid of one now and then. I also have a couple of pistols. My favorite being a Ruger American Compact 9. Good to be here.