I have both 35 Whelen and 350 mag. This past spring I put up some loads in the 350 in an attempt to more or less duplicate 35 Remington loads. Using the 200 Hornady RN and IMR 4198 I went from 39 to 43 grains. Here's what I got from the 350 mag:
39 grs 2190
40 grs 2200
41 grs 2285
42 grs 2320
43 grs 2350
I had hang fires on all up to 41 grs but none with 42 or 43 grs, the best accuracy was right at 2".
I later tried the 200 Hornady RN and IMR 4759 with pretty much linear velocity oncreases from 31 grs at 1885 up to 39 grs at 2330. No hang fires at any level and the best 3 shot groups of 0.8" and 0.4" but most around 1 1/2".
These loads came from the old IMR reloading pamphlet and, of course 4759 has been discontinued.
With the 350 and 35 Whelen being pretty close twins these should be pretty close.
