It is stupid to even think that you could take a shot at a Deer at 1,000 yards with a .223 and I don't care what length or rate of twist the Bbl. is. As far as a .308 not being a 1,000 yard weapon I know personaly of several people that got too meet their Buda many years before they thought they would with a 3 1/2 lb. squeez of a Winchester Trigger. Let us also remember that a .308 is also a 30-06 slug or visa versa.
Semper Fi!
Bill 8541