Winchester always came with sights appropriate for 170g bullets. Folks try the 150s cause they are faster and flatter but find out they have to change sights and deal with the fact that the trajectory difference is under 2 inches, eg about the same as shooter error.
Lighter will always be out of calibration, and often less accurate.
I've always preferred the federal powershock170g in the blue box. Plenty accurate, hit harder than the faster150s, and every win or marlin I ever owned with factory sights put them on the bullseye