I guess that I do to much reading. Ran across this info on another website. What do you think?
.223 Rem — Not A Competitive Option
I would stay away from the .223 Remington. On paper the 90gr VLD will shoot inside most .308 Win loads even at a 1000 yards. But in reality, on average, the .223 Rem, regardless of what powder/bullet combo is used, cannot compete with the .308 Win. [Editor: The equipment lists at major F-TR matches will confirm Kovan’s conclusion here.]
On a good calm day the 223 ahead of a good shooter will do well. Not sure about 1000 yards though! Get some switching winds and I think the 308 would be king. Just my 2 cents worth. Have not tried either to 1000!