.223 Brass - Commercial vs. Military


April 2, 2007, 07:25 PM
I was under the impression that the interior demensions of the Nato 5.56 brass was different than the commercial .223 and as a result you had to be careful as to what recipe you were loading. In my Speer #13 book it states that IMI brass was used, and as such you can also use commercial .223 brass safely with the listed recipies. I hate to question Speer, but is this common? (IMI is Isreal Military Nato ammo so we are talking about loading .223 and 5.56 in 5.56 cases and in .223 cases interchangably. ) This has to effect .223 ballistics right?

By the way, I see IMI .224 new bullets for sale on ebay. Is this any good? I hate to buy from an unknown source. Who knows what you actually get.


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April 2, 2007, 09:05 PM
It is my understanding that military versus civilian case capacity is very little to none in the 223 cases. I have some 62gr SS109s coming from ebay but not sure if they are IMI.

April 2, 2007, 09:15 PM
i've always heard military brass (specifically lake city) is thicker than commercial in 223/5.56. the result is that you should back off starting loads by an additional 10% when using commercial data with military brass.

however, it could be one of those internet /gunstore rumors. seems prudent to back off on the starting loads. worst case is you spend a little extra time. (as opposed to galactically bad worst case blowing up your gun and killing yourself)

years ago, i bought a ton of IMI bullets from wideners. they rocked. they stopped offering them a long time ago though and so i've been forced to settle for m193 pulldowns. if i could verify their authenticity, i'd buy a bunch (at the right price)

April 2, 2007, 09:52 PM
i've always heard military brass (specifically lake city) is thicker than commercial in 223/5.56. the result is that you should back off starting loads by an additional 10% when using commercial data with military brass

I've read this too. Also differences in neck length?

I'm using winchester .223 brass with both ss109 and 55 gr v-max bullets.

I pressure tested both.So now I start with max safe loads and back down to try to discover most accurate loads.

I'm optimistic. So I'll back down only about .4 gr for each.

And am now ABOUT [other projects (http://www.prosefights.org/nmlegal/voidjudgments/voidjudgments.htm#brzezinski)] ready to load, in DECREASING charges to test for accuracy. Now that I've established max varget charges for both ss109 and 55 gr v-max bullets.

April 2, 2007, 10:01 PM
I have read time and time again that military brass is thicker than commercial brass and this causes pressures to be higher in your rifle. I can't test pressures but it seems prudent to watch for signs of high psi if you load the military brass to same specs as commercial. I use both kinds of brass and back off on the military brands. My chrony shows that I lose little by backing off 10%. I am more of a chicken than a wildcatter so I tend to follow rules pretty closely for about the last 20 years of reloading, besides, my guns last longer that way.

April 2, 2007, 11:13 PM
Military brass is usually thicker than commercial. I never use commercial if I can get military. Military is higher quality overall.

April 2, 2007, 11:31 PM
i don't buy the military brass being higher quality part. even assuming we're talking about lake city and not Guatemalan brass or something... and equally obviously, there's a wide spectrum of quality in commercial brass. you're still not going to get the level of consistency with military brass you get with some commercial.

April 2, 2007, 11:50 PM
Thanks for all the responses, but... If I load to military spec in commercial brass wouldn't I get low presure loads? I can't believe this is a good thing.

I have also noticed that sometimes when I buy Federal American Eagle .223 it is stamped LC. I know, I know they call come from the same place, but now I can't tell the difference between the commercial brass and the military brass. Unless, there is no difference.


April 3, 2007, 03:40 AM
You need to get a chronograph and try different types of brass with the same load (not MAX) and see if there is a difference or you can fill the different cases with water to measure case volume. I believe Iíve read that there is a difference between different manufactures brass, but that the military brass is not necessarily thicker than commercial. This was for 223 / 5.56mm.

Iíve also read that in 308 there is a difference where you have to reduce powder charges in military brass (itís thicker) vs. commercial.

April 3, 2007, 12:10 PM
From experience, I have found LC from the 04, 05, and 06 years to be thinner than the 90s. I haven't weighed any, but I figure it's comparable to commercial Winchester brass.

Recent Lapua match .223 brass is thicker than recent LC brass. I had to drop my 80gr 600 yard load .5gr when I switched from LC to Lapua.

I am basing this on my chrono results. 24.5gr of RL15 behind an 80gr SMK in LC brass has the same velocity as 24.0gr or RL15 behind an 80gr SMK in Lapua match (in my specific rifle).

April 3, 2007, 02:23 PM
while there is often a difference in case capacity between military and commercial brass, it isn't enough to matter except in the case of .308/7.62, where you should begin lower than with commercial brass.

April 3, 2007, 02:28 PM
I weigh several cases from each lot of LC 89, LC 91, WCC, Fed, IMI, etc. Then, after I have worked up a load with one lot, I can check a batches average weight and know where to start with them.:)

April 3, 2007, 03:05 PM
I recently posted about a 10 round batch experiment I did with FC brass (basically LC for commercial market). I wieghed into 3 batches light, medium, and heavy and loaded them all the same powder charges and type 26.0 grains of RE15 under a 60 grain Vmax with a 205m primer seated to 2.29. The heavier brass made a 2-2.5 inch group at 100, the med 1.5-2.0 inch and the light made .75-1.00 at 100 yards. The light stuff wasn't actually even military type it was FC commercial brass and it was 4 grains lighter than the heavy military type brass. It makes a difference I think.

April 3, 2007, 03:31 PM
I have weighed a bunch of different types of boxer .223 cases. I have thousands of LC, a couple of thousand IMI, at least a thousand W/W, hundreds of BHA, FC, R-P and every type of scruffy foreign piece of range pickup brass that is has been fired only once.

When I get enough to have a decent statistical population, I have weighed them.

And the resultsÖ. .223 brass is very consistent in weight regardless of brand. I mean like a couple of grains difference. Not like 308 where cases by the same maker vary by 20 grains between lots. No joke, Federal Match ammunition the weight was from 155 grains to 170. 30-06 is about the same, weight all over the place, by year, by lot.

For slow fire prone, I shoot one brand, same number of times reloaded. Might make a difference in group size at 600 yards. But I know, by experience, that out to 300 yards I have not seen a difference.

The human error is the largest error in the system. And that can only be reduced through the experience of shooting.

April 3, 2007, 03:54 PM
Everything you ever wanted to know about .223 and 5.56


April 3, 2007, 04:03 PM
Everything you ever wanted to know about .223 and 5.56


As informative as the Ammo Oracle FAQ is, the content doesn't address this topic, which is brass thickness of military vs commercial brass.

April 3, 2007, 04:16 PM
I wondered this myself a while back and decided to do a test. I loaded my favorite .223 loading into FC, Rem, Win and LC brass. Only change was brass, all loaded at the same time. I took all out to the range and tested em over a chrono for speed and accuracy ( 10 rounds each). All testing one batch after the other.

All grouped the same with no sign of wandering or group adjustment, all velocities were within normal spread for this loading. Brass and primer showed no signs of any overpressure and no other firing oddities were noticed.

The load I used for this is a 55 gr Nosler BT
24.5 gr. of H335
over a CCI BR primer
Fired out of a Savage 12FV

If there is a difference you might notice it with max pressure loadings but I noticed none with this load. while it is recomended to drop the load a bit and work back up when you change any component or batch/lot of component, I did break the rule for this test.

April 7, 2007, 12:11 PM
From the Sierra manual (5th) in the Gas Gun Reloading section (page 176):

"The conventional wisdom to reduce loads with military brass is familiar to most reloaders and is generally good advice. The rationale here is that the military cases tend to be somewhat thicker and heavier than their civilian counterparts, which in turn reduces capacity and raises pressures. This additional pressure normally requires a one or two grain reduction from the loads show in most manuals or other data developed with the commercial cases. While this is most often the situation with both 308 Winchester and 30-06 cases, it is less true with the 223 brass . . . . There may be no need for such a reduction with the 223."

I have not seen significant differences among the wide variety of commericial and military .223/5.56 brass I've used.

April 8, 2007, 01:11 PM
CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.

308 brass military "LC 74" 179.2 gr
308 commercial Winchester 156.8 gr

The SAAMI registered maximum average pressure for 308 is 60kpsi with a proof pressure of 78kpsi to 84 kpsi.

IMHO, the maximum pressure this 1892 Mauser large primer case head could be loaded to would be 62kpsi factory or 65kpsi handload for a specific rifle.

.223 brass military "LC 98" 91.9 gr
.223 commercial RP brass 92.2 gr

The SAAMI registered maximum average pressure for .223 is 55kps with proof pressure of 71.5kpsi to 77 kpsi.

IMHO, the maximum the maximum this small primer rimless case head could be loaded to 69kspi factory and 73 kpsi handload for a specific rifle.

What does it all mean?
The problem with 308 military brass gets confused with .223.
The 223 military brass is not thicker, and the safety margin on 223 handloading is more like 32% than the .308 safety margin of 5%.

10 Years ago I started handloading with a Rockchucker Kit that included "Speer 12".
By the time I realized that the loads listed were in order of Velocity, but not at the same pressure, that the start velocities were made up,
and that the optimum powders were often not used, I was frustrated.

Whatever it says in "Speer 12" or "Speer 13", think of it as a recipe book fabricated by a committee, and only distantly related to any source data collected with controlled variables.
It is not a handbook for engineers.
It is IMHO, schlock.

April 9, 2007, 07:41 PM
So yesterday I decapped some of my brass and found that the LC and the FC commercial (american eagle in the red box) Looked exactly the same, and even the headstamp on the FC said LC on it(the 62 grain had the LC, the 55 grain had the FC headstamp). Not only that but the commerical brass also had the military crimp primer in it. I think it's the same thing.

April 18, 2007, 01:43 AM
You might look here -


April 18, 2007, 02:45 AM
You don't need to use the same brass listed in your manual. Any commercial brass will do nicely.
IMI does indeed make military brass and ammo. However, they also make commercial spec brass and ammo.

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