To compare the .35 Whelen and the 9.3x57, one should perhaps compare them in the same action of identical strength.
: First some basics. The .358 has a .358" groove diameter, while most 9.3's have a .358 bore diameter.
: An example of comparrison.
: Using the same weight bullets, the 57mm case in 8mm will generally be found to develop the same velocities at the same pressures as the '06 case in .308 calibre, using the same weight of bullets. Sectional density favours the smaller diameter bullet for any given weight, however this advantage is very small and usually not recognisable to any extent within normal hunting ranges.
: The comparrison of the 9.3x57 (on the 57mm x 8mm case) and .35 Whelen (on the '06 case), in the same action will give virtually identical results, given the same weight bullet, ie: velocities will be virtually identical at the same pressure.
; In the more common Swedish '96 action as the Husky M46 and M46A uses, we keep the velocities and thus pressures a bit lower, yet still completely capable of taking most game here and afar. My 'maybe not so weak' little M46 generates 2,170fps with a 300gr. RN of interlock or bonded construction, where as the original load which made the 9.3x62 famous, it's 286gr. bullet's velocity was 'supposed to be' 2,175fps, but probably fell slightly short of that. Mine were chronographed and proven. As to presure, they showed only .0002" (2/10,000") web expansion on firing, with low enough pressures that the necks to expand all the way. No, not becasue they were work hardened. Such our modern powders work wonders in some cases.
; So what we have is the 9,3x57 being virtually identical to the .35 Whelen, given the same action, whereas the 9.3x62, due to it's much greater capacity, being slightly better than the .35 Whelen Improved ( as both have similar case capacities.
: In the case of the 57mm case as opposed to the '06 case, the 57mm case matched the speeds of the greater capacity case due only to the increased groove diameter of it's bore increasing the expansion ratio of the powder, thus produced identical velocties with the same bullet weight.
: In the case of the 9.3x62 and the .35 Whelen Improved, since the case capacities were almost identical, the larger exceeds the Whelen in velocitiy due to the 9.3's greater expansion ratio.