Moonie,

I just checked the specs for the 9,3x74r. The rim on the 9.3 is .052 and the Win is .046...so good there

The base of the 9,3 is .465 and the Win is .415...so good there.

The rim dia.: 9,3....524 and Win .502...so good there.

The shoulder of the 9,3 is only .001 smaller than the base of the 375 Win, so there is no problem with taper...

I think I'll try the 9,3x74r case. In all actuality, I could just chamber it to 375 FM, as 475Guy suggested, but that isn't as much fun as having my own 375LUV2...I have a sh.t load of 9,3 brass and an extra set of 9,3x74r dies that I could have the neck opened up to .375 for much less than some wilder "cat" custom made...now for the reamer...

I have a set of 300 H&H FM barrels in my set that were once 30-06. They have worked out well...well enough that I would not worry too much about the 375FM chambering.