I shoot the same Winchester Supreme Ballistic Silvertips in my .270. The black coating on the bullet is lubalox, not moly. Not bad for the barrel in the least, supposedly the lubalox reduces the pressure needed to swage the rifling into the bullet on firing and also reduces copper fouling which is what degrades accuracy and makes you need
to clean the bore. Shoot them all you want (and can afford, they are pricey
) and don't sweat whether anything from Winchester is going to hurt your rifle.