Re: AR ammo
I have and still shoot Wolf ammo in my Bushmaster AR and have never had any problems. I'm sure it's not the most accurate stuff available, but in a SHTF scenario, tight groups should not be your #1 concern. For high volume practice, I think it's fine. If you're looking to shoot neat little groups, buy some match ammo. Wolf is dirtier than some, but If you clean your rifle after a day of shooting, this isn't a big deal.
I have several cases of better quality brass case ammo that I save for a "rainy day". I practice just enough with the good ammo to know how it performs compared to the cheap stuff, and when practicing for longer range accuracy.
Wolf .223 ammo, at $335 a case (last time I bought it) allows me to practice more, and that makes me a better shooter.
In my opinion, that makes up for any lack of accuracy.