Is Lake City .223 and .556 brass identical?

That's a good question but ... I kinda doubt-it.

I just don't know for sure but I seem to remember they use different cups for their milspec brass which, of course, is thicker but ... I just don't know for sure.

Best way to tell, imho, is to weigh each ... make sure it's decapped and thoroughly cleaned. I'll go out there and grab a couple of pieces and put'em on the scales later-on when I get a chance. I've got a bunch of both so I should be able to get some good samples.

I guess cases would really need-to-be sliced-down the middle and put under a scope to really tell. I've got a ballistics scope out there I could fire-up and I could probably use a dremel to split some cases.

Are you worried about running mixed batches using the same loading data or ... just worried about the .223 headstamped stuff holding-up to your AR ejector?

Scout21 said:

I've got a bunch of range brass in .223 and .556, the majority of which is Lake City. I'm wondering if the only difference between them is headstamp. I was getting conflicting answers in my research.

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Brass capacity for LC mil brass is the same as commercial brass. The primary change is the case head is harder. Starline 5.56 brass has this same change over its standard 223 brass.

Good overview here: https://www.accurateshooter.com/cartridge-guides/223rem/

LC brass is desirable to some long distance shooters. I like it myself.

I don't sort by head stamp. Last time out. I was shooting clays at 200 yards with mixed H.S. With my mini 14 and axis.

What distance are you shooting at? I normally shoot my AR at 25~50 yards, and sometimes stretch it out to 70 yards or so. I can usually get 2~3 inch groups at these ranges with open sights and imperfect eyesight.

I do find my groups tighten up when I've sorted by headstamp before loading.

chris

Scout21 said:

Frankly, I'm mostly looking for an offhand blasting load for my AR, so 2" or less would be acceptable. Even if the brass is different it may not make enough difference to make a difference. I'm more curious than anything.

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If you are behaving yourself and not loading hot... you won't be able to tell the difference between .223 and 5.56mm brass. Truthfully, if you are using cheapo 55grn FMJ's, those would be your limiting factor, not the brass.

Although I'm OCD, and segregate my brass into separate lots, I load everything the same. I don't do that, for example, with .308/7.62mm brass.

Scout21 said:

his is my primary concern. I don't plan on loading them super hot, so I'm not too worried about safety. What I am worried about is having two different POI due to differences between the .223 and .556 brass. If I can get away without sorting them then it'd be great.

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Scout21 said:

Frankly, I'm mostly looking for an offhand blasting load for my AR, so 2" or less would be acceptable

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I'll preface this with "this is my opinion". If all you want is 2 MOA for fun range work I don't think you need to sort. The caveat may be if you are shooting really hot 5.56. I do not sort brass for my AR, and I get as good or better accuracy than factory for the most part.

-Jeff

Just my feelings. Milspec .556 brass is on the long side and needs trimming to get under 223 Remington case OAL.

I love it until I have to trim a pile of it.

The case weight is the best way to tell, after fl size, deprime & trim. Only need to check 3 of each headstamp.


There are some heavy brands that will greatly increase pressure.

Mixed LC photos post #16. https://www.thehighroad.org/index.php?threads/using-matched-brass.908631/#post-12367666


Old examples of some heavies https://www.accurateshooter.com/cartridge-guides/223rem/

Pottimus said:

I love it until I have to trim a pile of it.

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By the time I get around to sizing and trimming up all my 5.56mm brass... it'll be 'vintage' brass...

I have found no difference.
If you are.going to use weight to test you will need to use cases from the same year, same lot would be better but almost impossible to know. Sometimes there are slight differences in the alloy which can change the weight of cases of the exact same dimensions.

Scout21 said:

Is the softer head of .223 known to have issues with an AR extractor?

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Not that I've noticed.

But if you get into sorting brass like LC then of course you will need to do so by year date stamp. All other brass with no data it doesn't seem to matter but to many the LC date is real important.

My main prairie dog rifle is a heavy 26” barrel, 204 Ruger, AR-15 rifle. I use the same headstamp cases for my ammunition. I do not sort cases by weight because I do not shoot at ranges where case weight might make a difference. If I remember correctly, currently my 204 Ruger cases are mostly Hornady.

For 223 Rem plinking ammunition, I do not worry much about headstamp. Ranges that I am shooting at are relatively short compared to my prairie dog rounds.

I always consider a Lake City cases as good cases.