As I sit here I have the May/June2008 edition of rifleshooter in front of me and Lo and Behold, they wildcatted the 375 Ruger to 416. I know this is not what you are doing but I'll throw out some comments from the article. The 416 Remington mag has the same water capacity as the 375 ruger although the Rem. is longer. The 375 Ruger has 2.5 Gr more capacity then the 375 H&H Magnum and fits in a standard length action. Just as an aside the author of the article achieved 2570fps from a 22 inch barrel using Reloder 15, 350gr Barnes TSX all at 8.5 grs below max load. Sounds like this cartidge would be fun to play with.