Roc Doc
2A SNBI
I stay away from LC or any other 5.56 brass just so I don't have to fuck with the primer pockets.Weight changes drastically with case head thickness. There's zero chance you get similar internal volumes by weight.
Lake City is actually pretty good and dirt cheap. Sort by year if you want to get fancy.
Lapua is always a solid choice for great brass. Alpha, Peterson, and Norma are good, but harder to find.
Winchester/Federal/Remington is hit and miss.
SGA used to sell 600 round cases of loaded Lapua 55g FMJ .223 ammo for like 40 cents a round, so I bought two cases as blasting ammo, and now I have over a thousand rounds of premium brass.