The SAAMI spec. for rifle cases using the large primer is 0.078" - 0.082"
Small primer pocket rifle and pistol cases use a smaller flash hole size of .074" - .078"
European CIP brass use 1.6mm - 1.7mm flash holes.
Original spec on 6 PPC which we all know is the most inaccurate round out there is .0625
Seems that smaller is better.
