There's one thing I've recently learned about the 9.3 X 62 using RL-17; it's in the same league and ball park as the 375 H&H.
It's quite easy to get 2550 fps from the 286gr Nosler Partition and my 22.4" barrel Tikka. Because I can seat the 286 NP to a COL of 3.36", more powder can be used that what Real Guns used. Their COL was 3.22". This is from a new/modern rifle, so please don't try it in your vintage "whatever"!!!!!!!
From a 22" barrel on a 375 H&H, I could barely make factory velocity from a 300gr (2530 fps). Because the 286 NP has a BC of .482 compared to .398 BC for the 300gr/.375, the 286 NP, 9.3 X 62 exceeds the velocity of the 300/.375 at any range past 50 yds, exceeds it in energy past 100, in momentum past 200 and trajectory at any range.
Just thought someone might like to know
(And, I'm a big fan of the .35 Whelen!)
Bob
www.bigbores.ca