While the 87 grain load in the 250-3000 might be aimed at the 1-14" ROT rifles, the same bullet in the 257 Roberts would seem to be out of place given the lack of ROT restrictions and the other available bullet weights.
Maybe, maybe not. The 87gr. loads in the Roberts could've likely been to assuage gunner's desires for higher velocity/flatter shooting ammo, while using a suitably constructed bullet.
Like you say, maybe, maybe not.
Either way it is a moot point since nobody has offered an 87 grain factory load in the 250-3000 for many years, I have some white box Wincheter 87 grain 250-3000 and 257 Roberts factory ammo that I bought in the early 1980s.
