With F&S cash rewards, I've been buying the 200 round range packs at $49 before tax locally.  I've been thru 500 total, 2 x 50 packs 223A, and 2 x 200 round battle packs 223ADG, zero issues.  As a bonus the brass has non crimped primers and I'm on my 3rd reloading of some of it.  I don't generally shoot 5.56 for accuracy groups at 100, as all my optics on those rifles are in the lower power range or iron sights.  But I have zero'd a couple 1-6 scopes at 50 yards with it recently, and it can easily hold about 1 inch 5 shot groups at 50.  Rifles are a Ruger AR556 16 inch 1-8 twist carbine gas, and two frankenbuilds, an 18 inch 1-8 twist with mid length gas, and an A1 style upper 20 inch 1-7 twist rifle gas.

Till my brass collection wears out, this is my plinking ammo backup stash.