I am a Leupold fan, HOWEVER, when it come to long range they have a small tenancy not to return to zero. If you search the inter-webs you will see many stories about this. I have not heard of NF having that issue.
I wish I could say this was news, but over a decade ago I also asked for specs for ring screws and was told something wildly out of line. I confirmed it with them a second time before doing it, then I used the quoted number and had the screw head seperate. I sen the rings back and they claimed that it was all fine, admitting the mistake. I still buy from them, but they clearly have some dumbasses in support.