Great post Daryl_S!
What make of 235gr bullet did you find was to tough I'm quessing Speer?
If it is the Speer bullet my Speer manual #13 mentions down loading the velocity
to 2600ft/sec for use on lighter game like deer but thats in the 375H&H ctg.
But in the 375 win ctg they are showing a top velocity of only 2067ft/sec with 35.0C Re7.
I suspect this 600 ft/sec velocity difference is enough to cause the speer 235gr
hot core bullet to act more like a solid than a mushrooming soft point on light
game at the lower velocity level that 375Win operates at.