...I believe it is similar to the 375 FL NE 2"1/2 case necked down to .303 with a smaller and thinner rim. You can load lighter bullets. It nestles nicely in between your other calibers. The only issue may be brass availability in which case you could opt for an 8x65R which is a similar case and performance except it's not a NE so it's not as sexy :-)

Cheers
Rhodes

Rhodes, the 8x65RS is for the European hunter a good alternative to 300 H&H Flanged.
Don't know why it isn't more popular...
No matter what I would like to have them all - 7x75 R, 300 H&H F, 8x65 RS, 400/350 Rigby and the 375 H&H Flanged...