Set Headspace too far back on 5.56

[MMH]

Was not careful & set headspace back to 1.445" on my 5.56. Normally set to 1.455" which is about 0.003" looser than the chamber in my AR. Is case head separation an issue now or have I just reduced brass life?

 

[Deleted member fkimble@charter.net]

Definitely shortened life a couple loadings. But 223/556 brass fired in an AR, seems to die from neck splits, not head separations. Load and shoot. Just keep an eye on them.

Frank

 

[MMH]

how bad is it to remove a case with a separated neck w/ a broken case extractor?

 

[joshb]

how bad is it to remove a case with a separated neck w/ a broken case extractor?

The one time it happened to me I pushed a 30 cal bronze brush in the chamber and pulled back. It grabbed the case and out it came.

 

[Bill Norris]

I'd say you shortened the brass life somewhat. But if it's got some age on it I'd discard it.

 

[jelenko]

About 1/2 the time I've had a case separation the front part of the case has just come out as the rear part is extracted. I've used a broken case extractor a few times. Seems to have worked when I followed the instructions.
After firing these cases and cleaning the brass well, you can check for pending case separations by looking for a thin, lighter colored line where cases tend to separate.

 

[jepp2]

you can check for pending case separations by looking for a thin, lighter colored line where cases tend to separate.

Or even more accurate do the bent paperclip test.

 

[garandman]

Was not careful & set headspace back to 1.445" on my 5.56. Normally set to 1.455" which is about 0.003" looser than the chamber in my AR. Is case head separation an issue now or have I just reduced brass life?

Could I ask HOW you did that?


My 223 / AR brass stretches alot more than 0.003, so I'm not thinking I'd be too worried about it.

 

[NorCalMikie]

Broken Case Extractor. Don't go shooting without it!!
I have one for EACH caliber I shoot. Even a couple custom made, just in case.

 

[Walt Krafft]

I would load and shoot them, then anneal before you size them again.

 

[Ned Ludd]

Maybe, maybe not. FWIW - in my .223 Rem F-TR bolt rifles, Lapua brass grows as much as .007" to .008" on the first firing because it is made toward the short end of the acceptable range. When subsequently re-sized so that the shoulders are only bumped ~.001" to .002" from the maximum chamber dimension, it will last a long time with reasonable loads, even though it stretches markedly during that 1st firing. Along the same line, friend and fellow F-TR shooter once accidentally re-sized Lapua .223 Rem brass all the way back to its original/virgin [relatively short] base-to-shoulder dimension for several successive firings. It took about four repeated firings and re-sizing back to the original virgin brass dimensions before the cases started exhibiting case head separation. So in the case of Lapua .223 Rem brass, it's going to get stretched out on the first firing no matter what. The question you're asking is how many more can over-stretchings can the brass take before it fails and there is no definitive answer.

As suggested, inspect inside of cases of possible. An illuminated borescope can actually be used to look for cracks and/or signs of case head separation. If you think they might be bad, toss them - better safe than sorry.

 

[karrarararararar]

Don't even need a broken case extractor in a pinch. Just try to chamber another round and extract it. The round will pull the broken case out with it. I've seen it done a few times.

 

[Cemetery21]

^^^ In an AR, that happens automagically, although it is a bear to extract..... according to a friend.

 

[chapstix97]

Chamber a fired case or use brass bore brush into the chamber and pull out separated case

 

[243winxb]

M16A1 carbine- .014" head clearance caused case separations in the middle (more towards the neck), of the body for me. The next round would load into the neck part & misfire. When extracted, both came out.
Very scary when the hammer drops on a unlocked bolt.

About 1/2 the time I've had a case separation the front part of the case has just come out as the rear part is extracted. I've used a broken case extractor a few times. Seems to have worked when I followed the instructions.
After firing these cases and cleaning the brass well, you can check for pending case separations by looking for a thin, lighter colored line where cases tend to separate.

Great info above.

 

[M-61]

Very scary when the hammer drops on a unlocked bolt

Would that be called 'firing out of battery?'

 

[RJTodd]

Not unless it goes bang! It should be difficult to light off with an AR bolt significantly out of battery. The bolt/carrier/cam are designed so that the firing pin cannot protrude from the bolt face unless the bolt is locked. I’m sure someone somewhere has found a way to defeat the design, but it shouldn’t happen.

 

[M-61]

a way to defeat the design, but it shouldn’t happen.

Poor quality pic. 5.56 shot from a Stag Ar. Fired out of battery. Formed a belt so it looks like a 224 Weatherby while blowing other side of case out. Shouldn't happen however 2 ballistic labs determined it was the cause. Fired and blew the mag out of the rifle and really jammed. Stag was of zero help.

 

[RJTodd]

View attachment 1277526
Poor quality pic. 5.56 shot from a Stag Ar. Fired out of battery. Formed a belt so it looks like a 224 Weatherby while blowing other side of case out. Shouldn't happen however 2 ballistic labs determined it was the cause. Fired and blew the mag out of the rifle and really jammed. Stag was of zero help.

If you measure headspace of this fired case (ie datum line on shoulder), how much did it grow?? Another way of asking the same question, how far out of battery when the cartridge fired? The neck length looks about right just looking at the case proportions.

 

[243winxb]

The bolt/carrier/cam are designed so that the firing pin cannot protrude from the bolt face unless the bolt is locked.

True for a Colt M16A1 carbine.