Ed: A Federal engineer once told me to try 210s (or any non-magnum) if the charge did not exceed 79gr of powder. I have to tell you it worked wonders in the 375 and 338 accuracy-wise.
John Barnsness made the same suggestion and going from a magnum primer to the CCI BR primer made all the difference in my .300 H&H. I was really surprised. It shrunk the groups by 1/2.
