I've got all this once-fired Nato-LC 5.56 brass. I want to make as much of it as I can into match-grade ammo. So I start sorting it by head-stamp year but then I get to wondering if that makes any difference at all. As I'm sorting I'm noticing that even within a given year some headstamps look different then others and some have a different style crimp. So I'm figuring that there's likely to be as much variation of critical dimensions between cases of the same year as ones from different years.
So I guess that's my question: have you noticed any correlation between headstamp year and consistency of critical dimensions? Should I sort this way or skip that and proceed directly to sorting by case neck thickness / uniformity, case volume, case weight, etc.?