Without velocity data, I would have to guess that the Nosler bullets are getting out of the barrel faster and leaving earlier in the recoil arc. This will make them print "lower" at distance. If the velocities are the same then any difference would be due to the interaction of the barrel and the bullet or due to the difference in BC of the bullets.
Quite often, in a handgun or even a rifle, you might notice that a slower or a heavier bullet will actually print higher than a lighter or faster bullet. This is due to the barrel time and point of exit in the recoil arc. Temperature can have the same type of effect printing lower at higher temperatures.(higher pressure, faster velocity, less barrel time...)
It may be that the Noslers just print lower, even at the same velocity as the Remingtons. It could just as easily be 4" to the left or right or higher or anywhere else they want.
I would just pick the one you want to use and stick with it.
Good luck, love those contenders.