Re: 223 Ammo
You don't mention what type of rifle you're shooting; that will make a difference. I'm shooting a single-shot H&R with a slowish (1:12") twist, which limits me to lighter bullets -- 55gr or so and under. That being said, a lot of people do have good luck with the Black Hills ammo; mine loves the Winchester white box 45gr HP's, and Ultramax 40 & 50gr rounds.
The guys around here have way more experience at long range than I do, but I would say try some different types of ammo and see what your rifle likes. I enjoy reloading; for a .223 you won't save any money because the ammo is cheap, but you'll have fun working up loads.
As for my rifle, it's got a 24" bull barrel and a Bushnell 3-9X40 scope -- it'll never be a bench-rest competition rig; it's more of a poor-boy's getting started rifle. But I have a lot of fun stuffing bullets into .6" at 100 and 1.5" at 200 on most days. Desert jackrabbits & coyotes don't have a chance, and a javelina in February is going to really hate it...