Highpower shooters using the AR platform are using Rem 7-1/2 and CCi and Wolf magnums. Federals tend to pierce with hot loads. The M1A shooters are using Win LR, CCI Mil, and Fed 210M. The Longrange bolt gun shooters are using Wolf and Fed 210M in that order. The Wolf seem to get a smaller deviation shot to shot.
The older WinSR (silver) are harder than the newer (brass colored) ones. If you aren't shooting hot loads even the Fed205M primers are OK.