Those post 63 Winchesters (for several ways) were really bad. The first Post 63 Winchester was a 1964 model. My cousin brought it over and My brother and I took it out to our range. 12" group was about the best we could do with factory ammo.
Pre-64's and the later (I think maybe maybe around 1980) post 63's were fine. And I've had a few post 63's that were fine. But I'd be leary of anything made in the later 60's.
