When I'm picking up my cases,  is it a good idea to separate the .223 and the 5.56 cases? Or can they be mixed without issue?

I don't sort any of them.  I would have to put on my glasses.

To add just a little...   If you are picking up unknown brass, watch for ones that appear to have Mil-Spec primer crimps.

This crimp implies that the brass may be once fired (but you should always inspect regardless).

The crimp will need to be removed. These cases can be run as a separate group.

The commercial brass (the ones where the primers pop out normally), need close inspection to make sure their web thickness is the same between mixed brands.

When you find a major difference in internal volume based on those web thickness values, keep those batched separately.

I suggest you hand de-prime any range pick-ups their first time in order to help find the ones with loose primers or crimps.

Mine go in the same batch.

If I want to shoot a nice group I can pick out 5 or whatever of the same brand.

But I gotta tell ya, I don't think it makes much difference. I go over everyone with an eagle eye, primer holes all cleaned deburred, checked for over length and trimmed,

certain brass that I know is heavy or old can all be marked and shot with the same. I take a magic marker and color the case head red if I don't want to save them, shoot them for hunting coyotes or out in the tullies blasting rocks.

I cannot talk on the 5.56 vers .223 brass issue myself.

However, I think the general concensus is to get the most accurate rounds you should separate the cases out by headstamp.

Then if you want to get really anal retentive you can separate out the same head stamped brass by how much they weigh.

You can do this quicker with an electronic scale and a plastic grid meant for flourescent light fixtures:



I have the plastic grid, but just haven't found the time yet to see if it makes that much difference.

My biggest improvement has been in buying and using a concentricity gauge to measure the runout of the case necks in processed once fired Lake City brass, but that has been the subject of one or three of my threads here so far.

There's something that has always bugged me about weight sorting non-uniform brass.

Small changes in the wall thickness cause relatively large changes in internal volume even for cases of identical weight.

That is, 0.001" change in wall thickness makes about a 1% case capacity (internal volume) change for cases of identical weight.  To keep identical weight, I assumed the cases wall mass was offset by case head thickness.  It takes very little change in the case head thickness to offset 0.001" change in the case wall thickness.  Are then we going to sort by weight and then by case head or wall thickness to get cases with the same internal volume?

This might be important to those who believe powder charges need to be hand weighed to ensure uniformity.  A 1-2% change in internal volume implies the need for a 1-2% change in powder charge (0.25 to 0.50 gr for 223; 0.4 - 0.8 gr for 308).

I think this is where Lapua shines - the cases are uniform in dimensions: walls and case heads.

Here’s my process for range brass:

I inspect every case, and separate range pick ups by caliber.  While I do this, I set aside any cases with crimped primers.  I do this all in one flow, using my Harvey deprimer.  I wind up with brass that is in groups of the same caliber, with GI versus commercial of each type further separated.

Doing it this way, I can easily identify whether cases with military headstamps are actually once fired, since the different resistance from the primer crimp is easily detectable.

For most purposes, commercial brass of the same caliber all goes together, though I often separate out nickel plated brass to use in special loadings.

To me, just about all usable .38 Special or .357 Magnum brass is interchangable, as is just about all commercial 9mm brass.  5.56 commercial brass is usually interchangable, though I pay attention for known headstamps - PMP from South Africa (still turning up some places) is thicker and needs a different powder charge; IMG and some others have a tendency for smallish flash holes, etc.

I consider LC brass to be LC brass, pretty much regardless of headstamp year, and the same goes for WCC brass.  I haven’t (that I know of) come across any 5.56 “WMA” brass (from Winchester’s Oxford, MS plant), though I have found plenty of 9mm from there.

Weighing same (or mixed for that matter) headstamp brass that hasn't been processed yet, in other words hasn't been uniformly sized and trimmed, is a complete waste of time/exercise in futility.    Think about when to weigh, if you are going to take the time to weigh at all, or you may not be sorting what you think you are.

I couldn't care less about what internal volume of brass is before I start stretching and cutting on it .......I care more about what the internal volume is right before I dump powder and stick a bullet in it, and how that volume compares with the next piece I pick up to load.   ymmv, but I can't imagine how.

I'd imagine sorting by internal capacity would work better, due to charge volume consistency.  Of course, you would have to fill each cartridge then empty it out on a scale or some sort of measuring glass for liquids.

Nice bell curve!!!!

Nope. Weigh the case without water, then weigh it full.

As long as your water is fairly pure, the volume is simple to calculate.  The density of water is 0.9982 g/ml (awful close to 1 gram per ml).  Using a digital scale (warmed up, all proper precautions, etc.) you can have it read grams and your work is essentially done for you.

The real problem is two-fold.  First there’s the tedious process of weighing, filling and reweighing the cases.  Then there’s the almost as tedious process of separating the cases by volume.  The second part is fairly easy to manage with those grids that go in drop ceiling florescent fixtures (see WimerainerDad’s post above, but it’s still fiddly and tedious.

With quality brass, you’ll usually wind up with large groups clustered closely around a particular volume.  Depending on just how anal you are, these large groups could be adequate for “proper” sorting.  Or not, if you’re really trying to shrink the last millimeter from your groups.

I think there are some ways to further streamline these processes, but I can’t think of them at the moment.

The thing is, IMO, all of that starts to sound almost insane - well beyond just a 'hobby' or a sport.  For instance, what does one do about the variability of the bead (the meniscus) that forms at the case mouth and the resultant variability in the water mass?

I guess if you have nothing else to do with your time...

If you are a professional or an amateur in search of a championship, just use Lapua.

Really, everyone thinking about doing this to improve accuracy should just use Lapua, instead.  Heck, buy 100 and test.

You know,... silk purse,... sows ear,... and all that.

whoops!

My bad.

I didn't mean for my post to be a step by step guide on sorting brass.

I was just throwing that out there as one possible option.

And I kinda figured that would be obvious or common sense to do that AFTER resizing and trimming.

You’ve hit that nail squarely on the head.  Sorting 5.56 cases by volume can be anywhere from finicky to obsessive.

For my purposes, I have kept to sorting by headstamp - sometimes by LC years - and pretty much nothing more.  I can see spot checking samples of sorted cases for weight just to see if suddenly LC is skimping on brass, or something like that.

But beyond that, my purposes involve something less demanding than neutering gnats at 800 meters, so I’ll spend more time making rounds (and shooting them), and less obsessing about electron micrography of flash hole edges.  

When I reload for my bolt actions, I use the same case lot, same brand, and sort out the ones that weigh the closest.
Not sure I have an AR that could tell the difference.

sorry WeimaranerDad, didn't mean for my post to come off as pickin at yours .... I quoted and highlighted the weighing part as I was typing on the topic of weighing in this thread.  No offense intended, I could probably stand to be a little more deliberate about how and when to quote and when not to.  cheers