7.62x39mm should only be loaded in batches sorted by headstamp. There are two reasons for this:
While Federal uses small rifle primers in their brass, most manufacturers use large rifle primers. This can be overcome by being careful on the priming stroke and using fairly hard primers, in which case you don't need to pre-sort here. So far, my Dillon 650's never had an explosion from Winchester primers, pressed in gently.
Berdan-primed 7.62x39mm brass is very common, and can break your decapping dies. That's what this page's headstamp reference is meant to address.
Known Berdan-primed headstamps
NK stamped brass - the N is actually backwards from a Roman N, which indicates a cyrillic origin. Along the bottom of the case, is stamped the year 1969. The primer is sealed in with a red lacquer.