muledeer,
In theory the 9.3 should be a slight bit faster. In practice, taking the variation in individual rifles ... I think the practical difference is non-existant. The bigger difference is how they're viewed bullet wise ... the Whelen seems to be viewed as a 200-250gr cartridge, the 9.3 as a 286gr + cartridge. Seems odd, but many years ago one of Australia's gunwriters was pushing how good the 9.3 is with a 232gr projectile particularly on our deer species ... but that view is rarely encountered in the bush or on internet forums.
Cheers...
Con