I need some input from you folks that have experience shooting 5.56mm ammo. I just received my new upper that was supposed to be a .223 Remington chambered but when it arrived, it was marked 5.56mm. With the 1500 coming up, what can I expect to find as far as best quality and price in this caliber? What brand would be best to buy for price and quality? I intend for it to be range ammo only. Thanks in advance for the help.