Go to Sierra Bullets web site then to their Match King bullets. All of their BC's are listed. Use their G1 value in Berger's software that's in the velocity range used; .490 for example for their 30 caliber 175 HPMK.
US Navy Distinguished Marksman Badge 153
Former USA Palma Team Member
NRA High Power Long Range High Master
NRA Smallbore Prone Master