Gonna be pretty hard to get that much 556 right now. Better chances with 223 but that’s not gonna be easy. Regular Cheap plinking 55grain 223 was sold out everywhere I checked. They only had the more expensive 62 and 70 grain green tips which I really don’t need. I prefer the 223 in 55 grain. Do you know your barrel twist rate ? Have you ever shot 223?
I buy from several different online retailers. there's plenty of ammo in all calibers to be had. I have no reason to buy now during this nonsense since i'm stocked for years to come. I have it shipped straight to my front door. life is good.