Kind uv in the same boat as the OP. I have a 9.3x62 that I build on a Whitworth American Field action, added a 3 position safety and NECG sights. With it I have a very nice walnut stock and a High Tech Specialties composite. Shoots most anything I put in it extremely well.
Been toying with the idea of a 375 Ruger. I n fact I have a #4 Rock Creek SS barrel, a M70 Classic Stainless magnun action, and a McM Hunter inletted for the M70 Classic. Just need to put it all together.
To add to the quandry, I have a M70 Safari 375 H&H, and custom 416 Ruger on a M70 classic action, and a 450/400 NE DR that should be in my hands soon.
With a 'battery' consisting of the 9.3x62, 375 H&H, 450/400 NE and 416 Ruger, I'm having second thoughts on whether I need the 375 Ruger, or for that matter, the 375 H&H. Ultimately the goal is to use one or two of them on a PG/DG safari. At this point I'm thinking about scrapping the 375 Ruger build, and parting with the 375 H&H. For what they might bring I could potentially pay for a good part of the airfare to RSA, or a couple more trophy fees!
