Here's a surprise. In this day of absurdly expensive ammo, Midway has a couple of deals on premium .223. First is Lapua 55-grain FMJ at $19.99 per box of 20. And there's Nosler 77-grain HPBT match ammo at $23.99/20. This is top-shelf ammo if you can use it. I don't have any .223 sporting rifles, but I do have an AR-15 that I built with a Faxon heavy barrel, so I got a couple of boxes of each to see how well the AR would shoot with top-quality ammo. It's shot MOA groups with no-name 77-grain rounds, so we'll see how much better it will do with Lapua and Nosler. The Lapua should shoot fine in any .223; the Nosler will require a fast twist to stabilize the long, heavy bullet.