spike's tactical .22 upper issues

Bought a used .22 upper. Cleaned it out, reamed the bore/ feedramp with polishing compound. It’s real nice and shiney. For some reason, it still doesn’t want to fwed, even when I work the action manually. I am using blackdog mags, so I doubt it’s a mag issue. Anyone have a similar experience? If so, how was the problem corrected?