.455" is the most common Ackley shoulder chamber, leaving fired brass at .454" due to case shrinkage after firing(av. .001"). This is also the shoulder diameter of the .308 family of ctgs. The shoulder angle of 40 degrees is also standard, which lengthens the body & increasing the capacity of that family of rounds from the .243 up to .358", for a slight improvement in ballistics - normally around 100fps, if held to SAAMI pressure levels.

My 9.3x62Oberndorf Mauser, as well as a factory Styer 9.3x62 rifle I obtained fired brass from, both have .455" shoulder diameters, leaving the fired cases at .454" & 78gr. capacity.