The Barnes and Nolser E-Tip recommend different seating depth requirements and since your new to reloading also E-tip they recommend mid loads as max and without chronograph that may be concern.
Barnes is .030 to .070 off the lands and E-Tip is .100" and my 30-06 the 150gr E-tip shot best .050" off and various tools you can use to measure base to ogive length. I never loaded any of the GMX bullets.
I hate to say this but just starting out reloading those may not be best bullets to start with might want to start with standard bullets build up loading skills then load. Barnes is sell ammo with their bullets and I'm sure there must be others depending on how much she shoot that rifle Barnes ammo may be cheaper in the long run for that hunt.