223 Seperation....

[Triple R Munitions]

well... this is the first encounter i have had with 223 in a semi-auto rifle. i have seen this on belt feds, but not an AR.... and i have no idea why it is doing this... i have ideas but looking for other opinions....



1. HEADSPACE!!!
2. over load
3. dirty chamber (burs etc)
4. weak brass..

i shot this in 2 AR's and had this happen on both of them. first i though #1 because, thats what happens if you have poor head-space. but i checked it with a no-go gauge, and it cleared. next i figured that the powder dispenser on my machine moved when i started to load these... went home and took a look at it was set were i left it. 25.2 gr of h335. (62gr FMJBT) now max is 25.6 so it is a hotter load, BUT it is within spec... then i thought it could be a burr in the chamber. i took it home and cleaned it quite well (looks like a mirror) and i did see some pitting in the top part of the chamber.... but no burrs... (pitting <?? how come...) then my final guess was that the brass is weak. this brass is ONCE-fired WCC-09 brass. from the police ranges... my final guess was that WCC made poor brass this year... hard to say but i ran out of ideas.... i am doing further testing with IMI, WCC-89, LC-09 etc or whatever i can find... i have used this load before and have no problems... so now i am here asking for some advice...

thanks
R

[ocabj]

It's a combination of the headspace of the resized brass and the fact that your brass was once fired from unknown chambers.

I've had this happen with once fired Lake City from unknown guns.

The best way to minimize case head separation is to resize such that the should is bumped the minimum amount necessary for the gun (.002-.003"). Then pray for the best. Hopefully the gun(s) the brass originally shot out of didn't have very loose chambers.

[Peter W Bush]

did you crimp the bullets?

[Triple R Munitions]

this brass is the Ranger 223 brass, from my understanding.... i wouldn't think that the cops have bad head-space... they have an armorer... but that's a possibility.

these Cartridges are crimped.

[ocabj]

this brass is the Ranger 223 brass, from my understanding.... i wouldn't think that the cops have bad head-space... they have an armorer... but that's a possibility.

A gun can have good headspace, but still have a 'sloppy' chamber. For example, the body area of the chamber may be wider. This would allow for more case stretch.

[m1match]

What's with those middle 2 cases with the bullets driven back into the case???? If the neck tension on the bullet is insufficient, you could get the bullets driven back into the case, but firing such a round usually results in elevated chamber pressures. The middle of the body of those cases has an expanded ridge, but the bullets are still in the case??? If those were fired cases, I wouldn't think the bullets would still be there. The other thing is the top and bottom pieces have separated in the middle of the case body. Usually when you see head separations they happen just forward of the case head.

[ocabj]

The bullets are not driven back into the case. Look closer. It's a case head separation where upper half stayed in the chamber and the next round fed into the chamber, placing the top half of the separated case onto the next loaded cartridge.

[Cokebottle]

Makes me wonder if that isn't what was happening in that youtube video where the AR blows up in the guy's face... he hit the assist several times before firing.

[Triple R Munitions]

well, a sloppy chamber would show signs of a bulge at the "web" of the case. none of the cases that are once fired show that sign, but i will mic them and get back to you. i will size a case then mic it, then do it again with a fired case.

i did find 2 live rounds that were unfired in that bucket of 223 brass, so i can mic those too.

when the "half" shell ejected and the "other" half stayed put, you could feel that the gun did not action correctly. i did pull the trigger, but the hammer just dropped and did NOT set the round off. PHEWW!


ALSO! my extractor is also ripping off part of the case. this only happened 1 out of 100rds.... maybe that would give you something else to think about....

the primers are just at the point were it is about to flow into the firing pin hole.... it is a hot load, but it is still in spec.... FYI..

[kurac]

I have never seen that one before. If the headspace is not excessive, could it possibly a case of the bolt unlocking prematurely?

[ar15barrels]

Bad brass, or the brass has been reloaded a bunch of times.
I don't think you get that from stuff fired one time in a really long chamber and then properly resized and reloaded.

I have had 3 or 4 of those myself over the last couple years.
Most of my brass is around 8 times reloaded though.
I have taken to leaving that specific batch of brass on the ground now as I don't want to reload them again and have to deal with more of them splitting...

[m1match]

ocabj- silly me- with your explanation, now I understand what I'm looking at. I'd agree with you and Randall- probably bad brass, but could also involve an over gassed rifle since the OP said he's also getting case rims ripped off.

[freakshow10mm]

Brass is wore out. Scrap the lot and move to the next.

[gregr266]

Is there a way to tell if the brass is worn out before this happens inside the chamber?

[Triple R Munitions]

thats what i figured... my lot of brass i got was bad stuff.... at least i did not sell any of it. i will scrap the brass and get a new lot in. but the 900 i have i will shoot up in my plinker rifle...

all the cases seem to be once fired..... well i am going to do some more tests and will get back to you on this...

anybody need some 223 brass?

thanks
R