Quote: Which .375 Flanged? 2 3/4 flanged or Flanged NE Magnum
The bullets designed for .375 H&H velocities will not expand in the 2 3/4 Flanged.
I presume you mean 2 1/2" flanged, I donīt know of a 2 3/4" flanged and no one in their right mind would have a modern double regulated to the 2 1/2". 300 grains IMO best