What happens when both cases are at maximum pressure with an optimized powder choice for each with all else being equal?
About a 150 ft/s advantage for the .280 depending on your exact bullet choice and what powders you consider available.
Two Questions:
1) What happens when both cases (308 and 30/06) are at maximum pressure with an optimized powder choice for each with all else being equal?
2) Do you have any data that show the 2.5 degree difference in shoulder angle and the 13 thousands difference in shoulder diameter result in a difference in performance?
