Extractor Marks on 5.56 LC Brass

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Lee Q. Loader

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I was sorting through a bunch of .223/5.56 brass that I picked up at the range a while back. Almost every piece of LC brass had extractor marks on it. The brass still had the primer crimps so it had to be once fired factory ammo.
Is this stuff overpressure from the factory or does something else cause this?

I know if I saw marks like that on my reloaded brass I'd quit shooting it!
 
The Army has a problem. Their little pop gun was maximized back in the 1960's. And then, they cut the barrel down to make an M4, which made the weapon system less lethal. Now since day one of M16 procurement, the Army had continued to bump up pressures, and they bumped up the pressures even more given the sandbox experience. The current US pressure spec has been withheld from the public by Army Ordnance, but rumors are it is within a couple of Kpsia of proof test pressures. Don't use US Army mil spec ammunition in your AR unless you want to experience cracked lugs and malfunctions.

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The Army has a problem. Their little pop gun was maximized back in the 1960's. And then, they cut the barrel down to make an M4, which made the weapon system less lethal. Now since day one of M16 procurement, the Army had continued to bump up pressures, and they bumped up the pressures even more given the sandbox experience. The current US pressure spec has been withheld from the public by Army Ordnance, but rumors are it is within a couple of Kpsia of proof test pressures. Don't use US Army mil spec ammunition in your AR unless you want to experience cracked lugs and malfunctions.

View attachment 864936

That's brass flow into the ejector port . That's WAAAAY up there in pressure , likely past proof loads right ?? That's a whole lot different then some extractor marks IMO although we don't really know if by extractor marks the OP means swipes or actual brass flow .

I have these in LC-14 and LC-15 308 cases that have ejector and extractor marks but these loads were not over pressure but rather softer brass , Ignore the arrow the photo was taken for a different purpose . Look at the upper right case and the ejector and extractor marks . These are once fired cases
Yglhxm.jpg

I'm working on a theory that the current brass being made on the high speed machines is softer then the traditional brass .

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Th cases that have headstamps that look like the case on the right regardless of year . Can be loaded to higher pressures then the cases with the little dots in the headstamp . I did volume tests with all of these cases and they only vary by a few tenths of a grain but I can put almost 2 full grains more of powder in the cases with out the dots with no pressure signs . While I'm getting sticky bolts with 1.5gr+ less powder and 125+ fps less with the cases that have those dots on them .

After talking with multiple reloaders and a multitude of testing . I've concluded the 1500ct lot of LC-14 cases I have are made with a softer brass then the other LC-09 , 10 , 12LR , Lapua and Rem brass I use . I just bought a 500ct lot of once fired LC-15 cases with the dots on the head and they also are showing extractor and ejector marks .

My thinking is those high speed machines that make the brass with the dots on them . Need the brass a tad softer to operate properly . I don't know this to be fact just a working theory .
 
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I'm working on a theory that the current brass being made on the high speed machines is softer then the traditional brass .

Much of the gear used in manufacturing brass is older than the 223/5.56 cartridge, so I doubt a manufacturing equipment evolution has driven any change in metallurgy for the brass.
 
a8zDoz.jpg Can you guys see the extractor sweeps on these ? They're on the top edge of the heads maybe I'll try to get a better picture . Anyways I'm wondering if the OP is talking these types of marks or the marks Slamfire showed . These were fired today in my very over gassed PA-10 .308 Win . As you can see these don't appear to be over pressured , Primers still nice and round , no cratering , extracted OK and yet I still get the smears on the case head .

If the OP could post some pics that would be great .

Ok this ones better
Jop6o4.jpg
 

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20191014_215302.jpg After reading the replies i was just now able to look back through my LC brass. All the brass with the marks is 14! I hope you can see it in the picture. Other years don't have the marks. Maybe it is the brass as Metal God suggested.
 
You know what else I just thought of? The range where I got these has a full auto rifle that you can rent. Maybe that has something to do with it?
 
View attachment 865525 Can you guys see the extractor sweeps on these ? They're on the top edge of the heads maybe I'll try to get a better picture . Anyways I'm wondering if the OP is talking these types of marks or the marks Slamfire showed . These were fired today in my very over gassed PA-10 .308 Win . As you can see these don't appear to be over pressured , Primers still nice and round , no cratering , extracted OK and yet I still get the smears on the case head .

If the OP could post some pics that would be great .

Ok this ones better
View attachment 865533

The one on the left looks like the brass smear is from loading the round not firing it. I had 1 bolt in my AR that did this. It's easy to test, just chamber a round and eject it without firing. If it's there you know the cause. This also shows up if your not quite moving the shoulder back far enough. The ar bolt has enough force behind it to move the shoulder about 0.002" when being slammed home.
 
I think like others that this is a problem with the gun being over-gassed. But .223 is so plentiful that if you are worried you should just throw it away. You will find more the next range trip.
 
The swipe, half circle marks, on the headstamp in the pics are not extractor marks. The are ejector marks. The extractor mark will be on the under side of the rim across from the ejector mark.
In Slamfire's photo you can see a line on the rim across from the ejector mark where the extractor pulled the cartridge case from the chamber. I have seen this with 223 ammo that were fired from rifles with rough chambers.
The swipe marks from the ejector will differ in one rifle when shooting different brands of ammo, depending on how soft the brass is and how hot the ammo is loaded.
I spend my days matching up cartridge cases from guns and shootings. Most often the breach face and firing pin strike are used to match them up, but when it comes to 5.56 and 223, the ejector mark is the easiest marks to match up.
So there are four things that will cause the extractor and ejector marks to show up more. High pressure, over gassed, rough chamber and soft brass.
 
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