Without the details on what your using I can only assume your wanting to use Remington short action, and a .257 x 300 WSM
. The factory box mag only allows for a 2.880" o.a.l. while the Wyats allows for a 3.000 . The 300 WSM has a o.a.l. case length of 2.100" and a neck length of .336" . I don't have a 100 g Nosler in front of me but I assume bullet o.a.l. is around 1". Your throat length will ultimately determine how far out you seat the bullet. You should have no problem seating a 100g Nosler BT down in the magazine with the info I have so far.