Winchester Western 55 grain 5.56 and Western 55 grain 5.56 are basically the same? I have boxes marked all three ways. Case head stamps vary slightly as well as primer color (some bronze and some silver). They seem to shoot well in my Mini-14 and I 'think' they shoot to same POI. For whatever reason the Winchester shoots good in it but the XM193 Federal is mediocre at best. I'm guessing the differences in the Winchester boxes and labels have more to do with packaging at the time of a particular lot but I'm not sure at all...hoping one of you knows:)