Case head separations. Are they a big deal?

[GLOOB]

I'm relatively new to reloading for rifle. I always thought case head separations were a really bad thing. I thought the case would get stuck in the chamber and that there'd be a noticeable blast of gas coming from the chamber near my face.

But now I've had 3 of them in a .223, and each time the only thing I noticed is that my gun didn't fire on the next shot. It's an autoloader. Each time, I found a broken case jamming the bolt open, and it was easily cleared by charging the bolt.

So, this is 3 case head separations in 400 rounds fired. Brass is "once fired" LC, full length resized, trimmed, and gauged with a Wilson case gauge. Is this a problem? Do I need to change my load? Are there any other bad consequences from these case head separations that could damage my gun (or me?)

Should I have the headspace measured by a smith? Or maybe just back out my sizing die a bit and see if the ammo still chambers?

 

[kelbro]

You need to check your headspace.

 

[GLOOB]

Hmm. So I have a Wilson case gauge. If I back out my sizing die a turn, size, then drop it in the case gauge, would I be able to tell if the headspace is too big? I mean, the case should be too long, right?

How else could I measure headspace?

 

[Hondo 60]

3 outta 400 is terrible odds.
I would do some serious checking of headspace & chamber.
Somethin' sure ain't right.

 

[GLOOB]

K thanks.

I wasn't sure if it was the brass or what. I heard a lot of LC brass is fired out of machine guns, so it's not good when you buy it once-fired.

Anywhoo, I've seen the go/no go style gauges for bolt action rifles, but I'm not sure how I'd go about measuring head space on a semi-auto. I mean, I'm not sure how to tell when the action is all the way closed within a hundredth of an inch, other than if the gun fires or not!?

 

[Waywatcher]

That's odd.

What kind of rifle?

Have you had any problems with other brass?

To me it sounds more like the brass was once-fired in a gun with the headspace problem. I'd be surprised if the problem is in your gun.

 

[medalguy]

Just FYI I load only military brass for my .223 rifles including a FA M16. I've probably loaded and shot over 50,000 rounds for that caliber in over 40 years of relaoding and I have yet to have a case separation in that or any caliber.

I agree something is seriously wrong. It MIGHT be that the brass was fired in a seriously imroperly headspaced gun but if it's military I really doubt that. I would buy a set of go/no go gauges from some place like Brownell's and check your headspace. You could have a gunsmith do it, but the cost will probably be about the same as the cost of gauges, and then you will have them for future use.

The case gauge will only tell you if the shoulder on the resized case is set back properly. It won't tell you anything about the headspace on your rifle.

 

[GLOOB]

I've only shot 200 factory rounds, no issues. It's an MSAR. Does a go no-go gauge work on a semiauto? It's kinda hard to tell exactly when the bolt is all the way closed. Learned early on that you don't want to ride the charging handle at all when you load it. I have noticed that I can make my reloads out to 2.95" (limit of the mags) and they still feed and shoot fine.

But other than eating up brass, would having too much headspace pose any threat of damage? Spare parts for these rifles is kinda non-existent. The gun shoots great. I never even noticed the separations except that the gun jammed, even though it's a bullpup with my face right next to the ejection port. Every time it happened, the entire case came out, but didn't make it out of the ejection port. The area of separation was well higher than the case web, which I read isn't uncommon in .223.

I'm up to a max charge of Varget behind a 75 gr bullet. Would backing off make any difference, or does it matter?

 

[Grumulkin]

Headspace could be the cause but ANY brass resized enough times will eventually thin above the web with a head separation the result. How many times have you resized the brass?

Head separations are a bad thing. In a strong firearm, you can get by with it but it's still something you should avoid.

 

[ranger335v]

"once fired" LC, full length resized, trimmed, and gauged with a Wilson case gauge. Is this a problem?"

In reverse order, yes, it's a potentially major problem when some 55K psi gets released. The seperations are occuring due to massively excessive shoulder set back with your FL die. If you back the sizer up until your cases actually fit your chamber it won't matter what your headspace really is.

All any drop-in gage can tell you is if the cartridges will (or should) work in any rifle ever made for that cartridge; your's work ... sorta. But, you're a reloader shooting a rifle, not the gage; make your ammo fit your rifle.

You need an adjustable case gage that actually reads in thousants, such as the Hornady or Sinclair tools that attach to the jaws of your dial caliper. With that you can measure the (relitive) shoulder length of a fired case, then match that with your resized cases to keep stretching to rational limits. I'd guess you're setting your shoulders back more than 20 thou now, it shouldn't be more than maybe 1 or 2 thou.

 

[rcmodel]

The very first thing you need to do is determine if it's the "once fired" brass already ready to break when you shoot it the second time.

You need to make yourself an L-shaped "feeler" out of a bent paper-clip, wire, etc. and reach down inside each case and feel for a stretch ring.

For more, read this post by Walkalong:
http://www.thehighroad.org/showpost.php?p=7669154&postcount=8

A case head separation in itself is not especially dangerous.
As you noticed, they always break in the same place about 1/2" or so ahead of the case rim.
This is where the case web taper ends and the thinner side wall begins.
That leaves the rear portion of the case still intact to act as a gas seal.

It was so common 100 years ago solders were issued broken case extractors to get the front portion of the broken cases out of the chambers. Cases are better now, and it is not as common, but still not desirable.


rc

 

[brickeyee]

If you keep pushing you eventually will have a complete separation that leave the front section of the case in the chamber and the case head on the ground.

You need to figure out why the cases are separating.

It can eventually result in gas cutting of the chamber wall, making it (at least) rough and even harder to extract a fired case from.

 

[Clark]

Can you see where my case head is starting to separate?
Usually guys get case head separation from pushing the shoulder back too far too many times.
I was getting it in this pic from just one shot with too hot a load in an AR15.

 

[Walkalong]

Can you see where my case head is starting to separate?.....................I was getting it in this pic from just one shot with too hot a load in an AR15

Yes, and there are certainly signs of serious pressure on that case head.

Usually guys get case head separation from pushing the shoulder back too far too many times

That and trying to get one to many firings out of it.

I recently shot a semi auto .223 at the range that was having near case head separations every few rounds. (We figured that out when picking up the brass. Bad enough that we could snap the case in half. It was a major brand of commercially reloaded ammo, supposedly using once fired brass.

I recommended he get the headspace checked to be sure, but it it was OK, then the brass was the problem. Either it was brass that had been fired numerous times, or over sized, or some of both.

Case head separations are just to close to catastrophic failure for me, so I go to great lengths to avoid them.

 

[918v]

gloob,

Adjust your FL die all the way fown to touch the shell holder, then back off one half turn. Size one of your 1x cases, drop it in your rifle and gently close the bolt on it. The bolt should not close. Turn the die in an eigth of a turn and size the case again. Try it in your rifle. Repeat until your bolt closes.

 

[ranger335v]

918v suggests a good process if you don't have a gage to show exactly what you're doing but 1/8 turn is much too large a change. Full min to max headspace (head to shoulder) for most bottle neck cartridges is usually around 6 thou and a 1/8th turn gives almost 9 thou of change in a single step, some 50% more than the normal SAMMI tolerance range. Cut those die changes to no more than 1/16 turn (about 4.5 thou) and you should be doing fairly good work but even that isn't as precise as it should be.

 

[Walkalong]

Agreed.

 

[GLOOB]

Well, I've gathered that my rifle is the likely culprit, from all the good info posted here. I did the paperclip check when I first got my brass. I threw out 2 out of a thousand cases. I'll go back and recheck the brass that's been fired from my own rifle, just to verify it's the problem.

Too bad MSAR is out of business. I can't see anyway I'm going to get the headspace corrected. The barrel is quick change, not threaded. So I don't see any way to make the chamber smaller. Likewise, spare barrels and bolts are hard to find. Ratworx is sold out and they're very expensive, anyway. Especially the barrels. I think the last one I saw for sale was $400.

Thanks Ranger. That's kinda what I thought, but it sure is nice to hear. I suppose the worst case would be my brass doesn't last quite as long, and my reloads won't fit in anyone else's rifle.

As you noticed, they always break in the same place about 1/2" or so ahead of the case rim.

Just FTR, one of the cases might have broken here, IIRC. The other two broke way higher, about a third the way up the case.

*Hmmmm. The plot thickens. I just did the paperclip test on a couple dozen cases and they were all fine. So I took out the ole Wilson case gauge, and most of my fired, unsized cases fit in the case gauge all the way. (One stopped way short, but I assume that was due to case diameter, since it stopped short a whole couple tenths!) I can't imagine that would be the case with too much headspace? Some of them even slide in by gravity, flush with the gauge. So maybe there's something else going on? I'd be happy to find out it's just a bad batch of brass or plain bad luck.

I'm glad that I carefully stored my true once-fired brass, separately. (I'm also glad my rifle throws brass in a 1 foot pile). So I can see how many firings I get out of them. It'll just take awhile. I don't reload rifle very often!

 

[fguffey]

‘Something else going on here’

”Hmmmm. The plot thickens. I just did the paperclip test on a couple dozen cases and they were all fine. So I took out the ole Wilson case gauge, and most of my fired, unsized cases fit in the case gauge all the way. (One stopped way short, but I assume that was due to case diameter, since it stopped short a whole couple tenths!) I can't imagine that would be the case with too much headspace? Some of them even slide in by gravity, flush with the gauge. So maybe there's something else going on? I'd be happy to find out it's just a bad batch of brass or plain bad luck”




”I've only shot 200 factory rounds, no issues. It's an MSAR. Does a go no-go gauge work on a semi auto? It's kinda hard to tell exactly when the bolt is all the way closed. Learned early on that you don't want to ride the charging handle at all when you load it. I have noticed that I can make my reloads out to 2.95" (limit of the mags) and they still feed and shoot fine”

“Does a go no-go gauge work?” No, there is no such thing, it is either or, it is a go-gage or it is a no go-gage, I am the only one that can modify a go-gage to a go to-infinity gage, not necessary however because I check head space on any chamber at least two different ways without a go, no or beyond gage, other methods are faster and more accurate, nothing but vanity would drive a reloader to measurements below .001 thousands, then there is memory, recovery, jump back, spring back or pop back, and some get so hung up on that I am surprised they get any reloading done, and if I spent my money on a chamber gage it would be a no go-gage, explaining the ration for that decision is/would be a waste of time.


Sounds cute “I use a head space gage” “You need a head space gage” “Check your head space with a head space gage” In the real world I do not get into this type of conversations, I do not deal with anyone that does not know the go-gage head space gage will chamber, meaning everyone that chambers a go-gage length head space gage knows the chamber is at least long enough for the gage, chambering the go-gage does not tell the user if the chamber has excessive head space. the go-gage will not chamber in a short chamber that will allow minimum length/full length sized cases to chamber, again, I determine the length of the chamber first, I am the fan of transfers and standards, and verifying, I am the fan of verifying.

I do not have less than 4,000 223 cases, new/unfired, once fired, sized, sized and primed and fired with primers, if at the end of the day something did not chamber I am able to go back and determine when the problem started, clips? Hundred of clips, they do not take up much space and the box is full.

The Wilson Case Gage: The user of the gage is the limiting factor, most on this forum refer to it as a ‘drop in gage’, If I take the time to use it I get the maximum use out of it, the Wilson has a ‘DATUM’ refered to by the the brain trust as a line, any how the Wilson case gage does all the work and makes it simple for beginners and the more experienced reloader, the problem most reloaders never get past the beginning status of reloading. With the case setting on the datum in the gage the length of the case can be measured with a straight edge (Wilson refers to the straight edge as a steel rule). Flush with the gage is .000 as in minimum length.full length sized, when using the Wilson gage I use straight edge and the companion to the press, the feeler gage.

There is another thread about a chamber with a bolt face problem, to determine if the case head is square with the case, again, use a straight edge (steel ‘small’ rule) and if you want accurate readings use the feeler gage, if the case head is square with the case body the straight edge will have a larger gap on one side than the other.

Paper clip, punched primers, case head separation, insipient case head separation and then there is catastrophic failure.

F. Guffey

 

[fguffey]

http://www.ombexpress.com/p-6788-like-new-msar-stg-556-223-bullpup-rifle-with.aspx

F. Guffey

 

[W.E.G.]

Reloads.

Most likely the problem is the reloads.

I've had separations with once-fired brass that was only reloaded once.
Not lots of them, but enough to be able to vouch for the fact that separations with once fired brass - especially if the second firing is in a gas-operated semi-auto - is something that does happen sometimes.

If you have a batch of brass that is showing that separation-on-second-firing tendency, you can drop your charge-weight 2.0 grains, and the problem will probably go away. But, that brass will still be susceptible. Those few separations on the first reloading are your red flag that you will likely get a lot more separations if you reload that lot of brass again.

 

[Deavis]

Does a go no-go gauge work on a semiauto?

Three gages that measure headspace in your rifle. one is a go, one is a no-go, and the last is a field. You can use them in any rifle, you just have to be a little more careful with the AR, i.e. run the bolt with finger pressure after lowering it gently. If the bolt closes on a a go gage, then your rifle has at least the minimum headspace, if it doesn't then it has to be reamed farther. Next the no-go gage is used, it would be nice if your bolt did not close on that, it is the maximum chamber headspace. Even if it just barely doesn't close, it still is within tolerance for the chamber spec. If it closes on the no-go, then you drop in the field, if it closes on that then you need to address that chamber.

Remember a GO gage is the minimum chamber size, it is NOT the minimum cartridge size, which is generally smaller than the minimum chamber size, otherwise it wouldn't feed. For a visualization, here is the 223 spec from SAAMI:

http://www.saami.org/PubResources/CC_Drawings/Rifle/223 Remington.pdf

Notice that the cartridge headspace (breech face to shoulder in this case) is 1.4666 - .007", i.e. 1.4666" is the longest length to the datum allowed and it can ONLY be shorter, not longer.

If you look at the chamber drawing, you'll see that for the headspace datum, the maximum is 1.4736 and the minimum is 1.4636", which is 0.0036" shorter than the maximum on the cartridge, so, a max size cartridge may not fit in the minimum chamber according to spec. Regardless, I hope that illustrates the point, the cartridge is smaller than the chamber for most situations, which is where the problem begins.

The headspace gage for your cartridge is measuring the shoulder setback and shouldn't move it farther back than the min cartridge specification. In other words the lower cut on your cartridge headspace gage should correspond to a number no less than the 1.4596 (max minus tolerance of 0.007") minimum but everyone uses different reamers and the minimum line may not be the same between manufacturers. For instance the lower cut (most setback) on my Dillon 223 gage is below the cut on my Lyman or Wilson gages.

All that being said, a few questions. One, did you measure the shoulder setback on the rounds you loaded? Two, what was your load?

 

[brickeyee]

There are also case gauges that function as a 'no-go' for a loaded round.

It ensures the case is not overly long.
A step on the head of the gauge shows the range the case head should be in when inserted.

 

[W.E.G.]

 

[Fisherdave10]

I don't know a lot about headspacing, but would it make sense just to take a non-resized fired casing from your MSAR and compare it to a completely resized or factory new casing?
Could that tell you if your shoulder is being thrown too far forward due to excessive headspacing?