Is all NATO Brass the same?

[Dave R]

My most accurate .223 load uses LC brass. But I've got multiple years of LC brass, and some NATO brass from other manufacturers. So how similar is this brass? Two questions:

1. Does LC brass vary from year to year? I'm wondering it my accuracy will improve if I sort by year?

2. I've picked up some NATO brass from other manufacturers, mostly WCC. Will I get better accuracy if I segregate the WCC from the LC? Or is it close enough that I'd be wasting time?

[TXGunNut]

I know folks who sort NATO brass by year stamps. This may be a job for a digital scale but for precision shooting I think you may need to stick with a specific lot and that could be problematic for range or purchased pre-fired brass. For my purposes I merely put all the mil-spec in one box and sort commercial brass by headstamp for semi-auto plinking stuff.
Same rules as any centerfire rifle for my Contender or the bolt gun I'm kicking around. Buy a large lot of good brass and sort by weight if necessary...

[medalguy]

For max accuracy, if that's your goal, I would suggest buying a large lot of new unloaded 5.56 brass from Scharch Brass:

http://www.scharch.com/products.php?cat=61