.223 / 5.56 Cases

[Good Cheer]

Just to satisfy my curiosity about "military" brass...
Wanted to compare case volume on various head stamps of brass.
So, took ten pieces of brass from each stamp, full length sized, trimmed and primed.
Filled ten cases level from a bowl of BLC2, doing my best to be consistent, then weighed the powder from the ten cases.

Here's the results I got with this brass:
Winchester = 303.0 grains
RP = 303.8 grains
Hornady = 298.6 grains
PSP = 302.5 grains
LC = 303.3 grains
WCC = 302.2 grains

Couldn't resist breaking out the calculator and running percentages averages, extreme spread, deviation from average. For that small a case volume it's certainly enough to make a difference in what load you build on which case.

[rhbrink]

Thats why it pays to start low and work your way up anytime you change anything. Especially brass and powder even if the powder is from the same manufacturer. Some powders seem to vary quite a bit from lot to lot in my experience anyway.

[Three44s]

+1 on powder lots having a BIG influence sometimes!

Three 44s

[Good Cheer]

I ran that survey of cases due to being told that military cases were of smaller capacity. Those results do not appear to indicate such.
Is there a suitable ball powder that is less sensitive to loading density?

[GabbyM]

Alliant has a new ball powder out for the 223.
Power Pro Varmint.
I've not heard any reports yet.

[spqrzilla]

The advice that military cases are of smaller capacity mainly applies to .30-06 arsenal brass. To a lesser extent it applies to .308Win/7.62NATO brass.

But I've never seen any indication that .223Rem/5.56mm cases differ much between commercial and military. There is more variation between them by manufacturer rather than by intended use.

[BruceB]

"But I've never seen any indication that .223Rem/5.56mm cases differ much between commercial and military. There is more variation between them by manufacturer rather than by intended use."

I agree 100%.

I once weighed samples from at least a dozen different groups of .223/5.56mm cases, that is, both military cases of various dates and factories, and commercial cases from a variety of manufacturers.

There was NO MEANINGFUL DIFFERENCE in the average weights of all the various groups. After that exercise, I stopped concerning myself with the subject. Occasionally I will check the average weight of a new batch of cases, but I don't lose sleep over it.

As mentioned, there definitely IS a weight difference between military and commercial brass in7.62 NATO/.308, and in the .30-06 brass as well.

[Gunnut 45/454]

Good Cheer
Ah sorry but .223 Rem/5.56mm case only wt 94 grains plus or minus! So I don't know what you used to weight them but it wasn't grains and it wasn't grams then they only come out 6.17g plus or minus! I do agree there is not much difference between them but 5.56mm has a thicker case head and are .010" longer at the neck . This why I trim 5.56mm to 1.760" and Rem .223 at 1.750".

[303Guy]

Gunnut 45/454, that was for powder charges. Still 303gr powder in a 223 case and the anomality went right past me! Decimal point in the wrong place maybe?

[missionary5155]

Good morning
The text says " He weighed the powder from 10 cases" Not one case.
Mike in Peru

[JeffinNZ]

I have a large quantity of FNB 5.56 brass I picked up at the range over a number of months. The headstamps are 04 and 06 and there is a 5gr variation between year of manufacture.

[pilot]

I have a large quantity of FNB 5.56 brass I picked up at the range over a number of months. The headstamps are 04 and 06 and there is a 5gr variation between year of manufacture.

Thanks, that reminds me, I have to take a sack to the range tomorrow. You can pick through the barrels there.

[JeffinNZ]

Thanks, that reminds me, I have to take a sack to the range tomorrow. You can pick through the barrels there.

Amazing isn't it? I made some nice "primer/powder" money picking up 5.56 brass, cleaning and sizing then on selling.

[pilot]

Amazing isn't it? I made some nice "primer/powder" money picking up 5.56 brass, cleaning and sizing then on selling.

I'm not planning on selling any yet. I got 55 rounds of 7.62x39 and a couple hundred 223 while waiting for the range to clear. I just want brass to load.

[JIMinPHX]

In my experience with .223 cases, PMP & RORG headstamp cases have much smaller capacity than the rest. LC, WCC, RP, FED & Winchester headstamp cases were all about the same. I have been told that older LC cases ran small, but I never saw that myself. I've tested most years of LC after 95 & a few as far back as the '70's.

Please be aware that some of the WCC stuff is made here by Winchester & some of it comes from IMI. I think that the Israeli stuff has a Q in the part number on the box or something like that. The two may not be quite the same.

[donald duck]

For my 7 MM TCU I check length to be 1.749. Run the .223 brass through a .25 die and then the .284. Only lost a few brass sizing a bunch last week. My case lube is Shaler Rislone drippings from adding to my Honda Pilot. I think it makes a good bullet lube. Loading 5.0 to 5.3 grains of Unique behind a 120 grain cast GC bullet. I did use 6.5 grains of Tite Group
behind 90 grain cast GC Bullet in my Rem. 700 .243. These loads are for paper punching and inexpensive to shoot.

[madsenshooter]

The volume of the .223 case used can make a difference in your results. I'd followed some other advice I'd found on here. The consensus was, there wasn't a substantial difference between military and commercial brass. So after getting a good accurate load for 6x45 in FC 06 cases, I made up the same in PRVI cases in preparation for a match. The accuracy was not nearly as good, and I could tell that pressure in the PRVI cases was lower. Though I didn't do too bad in the match, I think it would have been better if I had used the same lot of cases. When dealing with things smaller, seemingly minute differences can mean a lot! Here's how the test load on FC 06 cases shot a few days before the match. Though conditions were about the same, I imagine the groups increased to about 1.8".

[tomme boy]

Both have a trim length of 1.75" in every manual i have seen.

[GabbyM]

You can find deviation in web thickness from brand to brand. The 5.56mm Mil Surplus brass falls in within the range of variation between commercial brands. Even if brands weigh out the same they won't shoot together. Same with mixed head stamp Mil brass. Even mixed lot numbers on commercial brass is pretty iffy. The ten ring on a 200 yard I.B.S. Hunter Rifle target is about 7/8".

If you buy a bag of 100 new cases it’s best to get a 100 round box and keep them in that for life. Write the lot number off the bag onto the box. Half the time after you cull them you’ll only have around seventy five cases in the box. I’ve got around 500 243 Win cases with Win head stamps from three lots. Let them get mixed up after a prairie dog shoot years ago. They are sub par now. If they are just loaded with soft nose hunting bullets you can’t see the difference to much. You’ll get those flyers from a ten shot group. Shot about forty last week with 87gr V-Max and they made two vertically spread groups on the targets with a few hits in between at 200 yards. That’s after weight sorting. Was still shooting one hole groups. Just that all the groups weren’t in the same place. Then there were those in between. Shot five over the Chrony and one was over 100 fps out. Scratched that one then had an 8fps E.S. on the other four. Oh well.

[nicholst55]

In my experience with .223 cases, PMP & RORG headstamp cases have much smaller capacity than the rest. LC, WCC, RP, FED & Winchester headstamp cases were all about the same. I have been told that older LC cases ran small, but I never saw that myself. I've tested most years of LC after 95 & a few as far back as the '70's.

Please be aware that some of the WCC stuff is made here by Winchester & some of it comes from IMI. I think that the Israeli stuff has a Q in the part number on the box or something like that. The two may not be quite the same.

My experiences are the same as yours, Jim. I've reached the point where I won't hardly mess with foreign .223 brass, unless somebody donates a boatload of it to me!

Both have a trim length of 1.75" in every manual i have seen.

FWIW, all the once-fired USGI 5,56mm brass that I've ever worked with mikes some .010-.015" over that nominal measurement. Take a look at the dimensions on the link below, and you'll see why.

http://www.ar15barrels.com/data/223vs556.pdf