Question about brass prep for precision reloading Nato LC 5.56

[bigedp51]

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.?

It depends on your rifle I have two AR15s and a bolt action .223 with a heavy 26 inch barrel. The bolt action gets the best brass followed by my A2 HBAR and the carbine gets the unsorted left overs. And Lake City brass is the best brass the tax payers can have made and I would never think of letting any of my AR15s chew the rims up on Lapua brass.

Just run a test of 50 cases, sort by matching headstamp and then weight sort and load, then load 50 without any sorting and see if you see any difference. Your the one pulling the trigger and it will be a learning experience about your rifle and ammo.

And if you want to load ammo with the least amount of neck runout then buy a Forster full length die with the high mounted expander. I converted my RCBS dies by buying Forster expanders and spindle assemblies and I'm getting .001 or less runout after sizing.