5.56 - 223

User00007

Well-Known Member
Hi all, right don't crucify me on this question, as im new to reloading but someone advised me that you can re-size 5.56 old military cases to suit 223, ? is that right and if so is that what people use ?, I have also heard that old military spent cases are better as they are thicker ? - P.S I don't have a 223 just wondered if anyone currently used this brass :-|.
 
Yes you can resize 556 to use in a 223. The main difference between the 2 is in the chambering the leade in the 556 is a lot longer. Some people prefer thinner brass as they can get more powder in. I use GGG brass and its dam good stuff
 
Thanks Danny, just wondered that's all, and wondered why people don't just use old surplus military to reload with as it must be way cheaper than other brass
 
The main reason is probably because milspec ammo has crimped primers which is an extra step to get rid of. Also some milspec brass is pretty brittle so will need annealing before reusing
 
Thicker isn't always better in the rifles we have legally permitted in the UK. If we had self-loading rifles thicker would indeed be better.

But we don't. So the only real advantage is cost.

If they are cheaper go ahead. But if commercial, good quality, .223 cases are available I'd choose them if they were the same price. And yes beware the difference in capacity.
 
Most, not all, 5.56mm is poor quality brass compared to the better commercial products. Even where it is 'good', ie consistent weights, wall and neck circumferences around the case, properly annealed necks and shoulders, it has a lower capacity compared to Winchester, Norma, and Lapua 223. In such a small capacity case, that's generally a bad thing, reducing usable maximum charges and hence velocities.

However, there is another thing one really has to watch with ex-military 5.56. The Nato spec is very high pressure indeed in the standard 62gn bullet loading, nearly 62,000 psi. That is a punishing level. And gas-powered semi-autos are HARD on brass - they are whipped into and out of chambers in weapons whose headspace adjustments would sometimes give a civilian rifle builder a fit or two. Fired cases with their heads (ie bases) forced out of square to the cartridge axis aren't unknown. Massive cuts into the case-head / rim are often seen, this caused by the case hitting a peg ejector at speeds you couldn't approach in a manually operated firearm, and dents in the case-mouth / shoulder received by the case hitting the edge of the ejection port are also pretty common.

Then as noted primers are crimped into the pocket (to stop them backing out and causing a malfunction when fired in an automatic weapon with excessive headspace). This has to be reamed out after sizing / depriming before the case can be re-primed, or the entire pocket swaged.

So, ex-military brass can be good and reloadable, but it is a matter of being very careful as to what it is, where it came from, and looking hard at its condition. Generally, you get what you pay for things and the people who make military ammo churn it out in the millions at the very low prices that miserly governments will pay for it. The surprise isn't that there is bad military brass around, rather that some of it is as good as it is. If you can find once-fired Lithuanian manufactured GGG brass that has been fired in civilian rifles for sale, it has a good reputation.
 
What about standard .223 ammo (ie Hornady fmj training rounds or Geco fmj rounds) that have been fired through military semi autos? Assuming they look ok are they likely to be ok to resize?

I've picked up Federal brass fired from a H&K 417 (.308) and it had deep lines and ridges along the length of the case where it appeared to have expanded and been heavily marked by the chamber/extraction process. These looked like they were too far damaged to be worth reloading.
 
What about standard .223 ammo (ie Hornady fmj training rounds or Geco fmj rounds) that have been fired through military semi autos? Assuming they look ok are they likely to be ok to resize?

I've picked up Federal brass fired from a H&K 417 (.308) and it had deep lines and ridges along the length of the case where it appeared to have expanded and been heavily marked by the chamber/extraction process. These looked like they were too far damaged to be worth reloading.
H&K's have fluted chambers.~Muir
 
As to the brass thing. I use a boat load of US military surplus brass in my .223 bolt guns and have had nothing but success. US military brass (Federal, WCC, LC) is not thicker than commercial brass outside of normal LOT variations. Also, US 5.56 is loaded to 55,000 psi as is commercial 223 ammunition. This is SAAMI spec and measurement. Due to the way pressures are measured with CIP, the pressures for European 5.56 is at 62,000 psi. In researching military .223 brass to cut down to make 300 Blackout, I found a wealth of information on the subject, including weighing tests of .223 / 5.56. In some lots the military cases were lighter than commercial counterparts.

Crimped brass is a bummer but tools like the Dillon Power Swage make quick work of them.~Muir

PS: Throating of 5.56 NATO weapons and .223 weapons are different. The .223 has a tighter, sharper cone.
 
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The European stuff is very different to your US made 5.56, Muir. The UK's RG (the former government Radway Green factory) manufactured cases whether 5.56 or 7.62 are really heavy with noticeably reduced capacity compared to any commercial make. German MEN military brass is very good quality and strong, but again very low capacity. When I used to load 223 for a straight-pull (manual operation) AR-15, I had to reduce charges with 69s by 1.5gn for MEN compared to Winchester otherwise the pressures were so high that I'd have to fight to get the bolt open with the lack of gas assistance. I don't know about GGG which is now widely available in the UK as loaded ammunition (RG stopped supplying anybody other than government markets some years back) and which has a good reputation amongst high volume 223 shooters as I've never handled any.

I know from many posts on US based forums how highly regarded some Lake City brass is (and some of its 7.62 'vintages' were too amongst the M14 / M1A users when that was the rifle for XTC) but unless GGG offers a step change from previous supplies here, we've never had anything comparable. We never get any once-fired US brass here.
 
This is a good qualifying question too. If I'm talking guns with someone and the are telling me things that I have never heard of before, I ask them if they know what the difference is between .223 and 5.56. If they don't know it's how the chamber is cut, it's a good indicator that they may not know as much as they think they know. Also, it's real good question for a pompous ass behind the counter at a gun shop.
 
I've not reloaded 5.56 cases but the 7.62s I've reloaded or sized to .243 have had significantly smaller capacity.

If you have got a selection of 5.56 and some .223 then checking would not be hard.
 
Thanks Muir, what is the reasoning behind that? More reliable cycling? The brass looked too far compromised to bother reloading anyway.
Better performance under combat conditions. Easier extraction, cooler (tho i'm not sure about that one) and less fouling interference. The first H&K 91 I played with turned me off because of it. It's not a gun to reload for. Anecdotally, I am reminded that the second HK 91 I sold back in the 80's came with a beautiful test fire target and, as was found out when the new owner went to the range, NO chamber. Go figure.~Muir
 
I've not reloaded 5.56 cases but the 7.62s I've reloaded or sized to .243 have had significantly smaller capacity.

If you have got a selection of 5.56 and some .223 then checking would not be hard.
Yes indeedy: The 7.62 cases are heavier. I make 7-08 from them as well as all my 308 loadings. I have so much military 308 ammo and once fired brass that I haven't bought commercial in years.~Muir
 
Thanks Muir, what is the reasoning behind that? More reliable cycling? The brass looked too far compromised to bother reloading anyway.
The fluted chamber marks look bad but the brass is still reloadable, a friend had a H&K91 and we reloaded piles of ammo for it so much fun to shoot and very accurate,
We just tumbled the brass with crushed corncob for a few hours and loaded it up and shot it again, from memory we were getting 5 - 7 reloads from a case before they got beatup
to much, I used the brass in a couple of hunting .308's after the H&K91 was sold still have a few hundred left the flute marks have almost gone, the brass is LC 68 tough as old boots
 
No problems using mil brass regardless what the 'experts' say.

Had a H&K M300 22WMR that had the fluted chamber, If i recall they blabbed about it introducing an extra delay, it was stunningly accurate but suffered from a need of the action and chamber to be kept spotlessly clean.
 
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The reason for the fluted chamber in H&K designs is that the action is a delayed-blowback type. In a normal recoil or gas-operated semi or full-auto military weapon, the bolt remains locked to the barrel or in the case of machineguns a barrel-extension until the bullet is so far down the barrel that chamber pressures have dropped enough to start bolt unlocking and fired case ejection.

The H&K system started in the dying days of the Third Reich as a weapons research project and the engineers / designers fled to Spain in 1945 where the work was picked up by the CETME organisation and led to the development of a family of delayed-blowback action military firearms. Ultimately it returned to Germany as the H&K manufactured HK91 adopted for the newly reconstituted Bundeswehr as the G3 rifle.

As an aside, the Bundeswehr and German government actually wanted to equip its forces with the FN FAL or G1 in Bundeswehr nomenclature which had already been issued to early formations, these manufactured by FN in Liege. To do so, for the million or so rifles now needed, the Bundesrepublik sought a manufacturing license from FN to manufacture G3s in German plants which the former wartime Allies had closed down 'permanently' on the Third Reich's defeat, but were now allowed to go back into business as a concession to Germany joining NATO as an ally in countering the Soviet threat. This caused a huge political row in Belgium which was still smarting in the 1950s over wartime German occupation and permission was refused at senior government level. Germany couldn't get the FAL, so turned to the German / Spanish design as an alternative and created the sole competitor to the FAL as a result!

Blowback actions don't work for full-power rifle cartridges, hence full lock-up being the norm. The CETME / H&K system sees the bolt initially locked into battery by two rollers on the bolt sides which are forced outward by the firing pin as it travels forward to ignite the cartridge into matching cutouts in the receiver wall locking the bolt closed. As the firing pin returns inside the bolt, pressure on the rollers is reduced allowing backward pressure from the now fired cartridge case-head on the bolt to force it open and start rearward movement for the ejection part of the operating cycle. Pressure should have dropped enough thanks to the delay caused by the roller projection for this to happen safely. In practice, it was found that pressure remained high enough to see some fired cartridge cases still obturated in the chamber gripping its sides tightly and the bolt / extractor would tear through the case-rim leaving the fired case in situ and try to load the next live round into it. The fluting was adopted to overcome this by allowing some gas to escape into the chamber around the case body during the locked part of the cycle and 'float' the case inside the chamber acting as a lubricant in effect.
 
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