I was thinking about this today and it applies not only to the 35 Whelen but to other rounds like the 338-06 and so on. Since the 35 Whelen uses a 30-06 case could you use 200gr 30-06 data for a 200gr 35 Whelen?
That is, with the same boolit/bullet weight and parent case could you use that data as a starting point?
How would this react?
I was looking at an old Accurate Manual for data on AA8700 and found it listed for heavy 30-06 but not light 35 Whelen so this is what got me onto this line of thinking