I understand about the human pupil opening up to about 7mm in near darkness, so the theory is that any exit pupil above 7mm is "wasted" on the enduser. I do not agree with that theory. While only up to 7mm of exit pupil is necessary before exceeding the size of the pupil, anything higher still provides a brighter sight picture. Conversely, IMHO, anything smaller than a 7mm exit pupil begins to limit the low light capability of the scope. The NF scope achieves a 7mm exit pupil at only 3.4x, so any magnification above that shrinks the exit pupil until each reaches its minimum of 2.4mm at 10x. This might be OK for daylight use, but would be quite limiting in low light. Given the intended hunting ranges of up to 700 yards, and using the rule of thumb of 1x for every 100 yards of range, the NF scope at 7x would have a 3.4mm exit pupil, OK for quality glass in daylight, but I would think it would be a handicap for low light use. This is why I suggested the 50mm. 40-42mm would be OK as a compromise.
As to the fit of scope to rifle, I think the benefits of the larger scope for the intended purpose offset the aesthetic trade-off, but that is a personal choice.
I'm sure the 2.5-10x24 is a dandy scope, but we'll have to agree to disagree it's the best scope for this situation.
Take care, my friend...
"See Better, Shoot Better"