35Whelen factory loads are not all created equal IME chronographing - often under whelming - are never up to what my top level handloading can produce. So no would be my response to the question as to the "ideal" chambering for that. A 300 ultra and the like would be more ideal.
However with good handloads (not your premise) and the accuracy gremlins at bay, the 35 Whelen can be a 400 yd moose gun IMO - though I've not proved that myself in the real world. You would sight in about 4" up at 100 amd be point blank to about 314yds. Learn to shoot the trajectory past that to 400 -
http://35cal.com/longrange35.html
Good moose rifle chambering all the same IMO.