Case head separations. Are they a big deal?


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GLOOB
November 1, 2011, 11:34 PM
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?

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kelbro
November 1, 2011, 11:37 PM
You need to check your headspace.

GLOOB
November 1, 2011, 11:41 PM
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
November 1, 2011, 11:43 PM
3 outta 400 is terrible odds.
I would do some serious checking of headspace & chamber.
Somethin' sure ain't right.

GLOOB
November 1, 2011, 11:48 PM
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
November 1, 2011, 11:57 PM
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
November 2, 2011, 01:28 AM
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
November 2, 2011, 06:56 AM
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
November 2, 2011, 08:41 AM
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
November 2, 2011, 11:17 AM
"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
November 2, 2011, 11:29 AM
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
November 2, 2011, 11:39 AM
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
November 2, 2011, 11:54 AM
http://i757.photobucket.com/albums/xx220/ClarkM/AR15BlueDot18Gr33VmaxDSCF0027.jpg

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
November 2, 2011, 01:07 PM
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 timesThat 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
November 2, 2011, 02:00 PM
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
November 2, 2011, 03:30 PM
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
November 2, 2011, 04:04 PM
Agreed.

GLOOB
November 2, 2011, 09:30 PM
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
November 3, 2011, 11:47 AM
‘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
November 3, 2011, 12:10 PM
http://www.ombexpress.com/p-6788-like-new-msar-stg-556-223-bullpup-rifle-with.aspx

F. Guffey

W.E.G.
November 3, 2011, 12:13 PM
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
November 3, 2011, 06:28 PM
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%20Remington.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
November 3, 2011, 06:47 PM
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.
November 3, 2011, 07:26 PM
http://i227.photobucket.com/albums/dd7/rkba2da/ammunition/004-headspacegagessmaller.jpg

Fisherdave10
November 3, 2011, 11:15 PM
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?

fguffey
November 4, 2011, 12:42 AM
Fisherdave, measure before and again after, measure the length of the case before firing from the head of the case to itís shoulder, measure again after firing Ďagainí from the head head of the case to itís shoulder, the difference in length between the two measurements should represent the effect the chamber had on the case when fired.

I measure the length of the chamber first, GLOOB said:

ďI've only shot 200 factory rounds, no issues. It's an MSAR.ď

A good time to have measured his fired cases would have been after firing the 200 factory rounds. He could have saved a few for reference. A fired case should mirror the chamber, less snap back? It seems everything started going wrong after he started reloading, I am a big fan of standards, transfers and verifying.
The diameter of the case can be measured, convincing someone it is possible is another matter.He indicates some of his fired cases will not drop in and have to be forced in, for me that is a concern. His factory rounds fired in his rifle fit his Wilson case gage, some of his reloads after firing will not drop in.

F. Guffey

brickeyee
November 4, 2011, 12:44 PM
One way of dealing with old rifles that may not be as well made or have wear is to treat them as a wildcat and not set the shoulder back any more than needed for chambering the reloaded shell.

The typical die instructions (screw down the sizer slightly past the top of the ram stroke) is to ensure full sizing so the round will fit any gun of like chambering.

If you are using the brass in the same gun again you do not need to move the shoulder back to 'like new' or reduce the diameter to the cartridge max.

You can move the shoulder back only enough to allow easy chambering.

In some cases you may not need to move the shoulder back on every reloading, but will need to use a bump die after a couple firings.
It depends on chamber dimensions, brass spring back, load intensity, brass hardness, etc.

There are other tricks like loading rimmed or belted cases to headspace on the shoulder instead of the belt or rim that can also extend brass life and help prevent case head separation from repeated stretching.

fguffey
November 6, 2011, 12:27 PM
Set the shoulder back more than necessary: The problem starts with the chamber shoulder being too far forward in the beginning, that problem is compounded by the reloader that can not get the shoulder of the case forward with out firing it, a concept that is impossible for a reloader/fire former to grasp. again, my favorite case is the once fired case that has been fired in a trashy old chamber that was too long for the case that was fired in it. I have (again) a trashy old chamber that is .016 thousands longer than a minimum length/full length sized case (or .011 thousands longer than a go-gage length chamber), fire forming? not necessary, the 280 Remington case is .051 thousands longer from the case head to it’s shoulder than the 30/06, to form cases for that trashy old chamber I use 280 Remington cases, all I have to know is when to stop bumping?!!!! the shoulder back, as to bumping a shoulder back .037 thousands, sounds like the definition of bump should be changed to wreck or at least ‘change’ bump sounds like an accident, there is nothing I do that is an accident, I place the shoulder of the case exactly where I want it, and it never involves fire forming to move the shoulder forward, it has to do with moving the shoulder back . A fundamental method/technique is determining the length of the chamber first before reloading for 'that' chamber



Brickeye, Friends built 5 magnificent wildcats in 7mm, something between a 280 Remington and 7mm/06-7mm Gibbs with Ackley Improved mixed in, they made the reamer etc.. One of the two went to the range to test fire/fire form, 6 of the first 10 cases fired had case head separation, they used 1903/A3s, magnificently wrapped/unissued 03/A3 Remingtons, anyhow I was told my advise was not correct, it was as though their surprise was my fault, I informed them I could have told them if their new creation would work before they left the shop, I told them I could have fixed the problem had I been at the range long enough to fire form the cases, I then explained to them I was not a fan of fire forming, I informed them I was a form first then fire to get once fired cases when ejected. And that, as usual, did not go over very well. Then it got down to 5 rifles in all appearance were the same, 1903/A3, my advise on that matter “ You are not the first person to make that mistake” and I suggested testing all 5 before attempting ‘fire forming’ they changed their methods after the mistakes with the first attempt.

One of the two made dies, those that knew him were not interested in spending time enough with him to acquire the skills necessary, I was asked if I was interested years later if I was interested in attempting to make dies and or parts for the dies he made, and I said no, he made the reamer and dies for rifles he built, his dies were very different.

F. Guffey

bigedp51
November 6, 2011, 08:39 PM
Take a new unfired case or a full length resized case, a spent fired primer and just start the primer in the primer pocket, now chamber this test case and eject the case. The amount the primer is protruding is you head clearance or the "air space" between the bolt face and the rear of the case. The "head clearance is the amount the case can stretch and thin in the base web area that leads to case head separations.

On my Stevens 200 in .243 my headspace is .002 longer than minimum or GO, If I full length resize the case without compensating for this .002 the FL die will create .004 head clearance and the case can stretch .004 each time it is fired and promote case head separations.

The following is from Reloader Magazine.

http://i122.photobucket.com/albums/o254/bigedp51/308fail.jpg

http://i122.photobucket.com/albums/o254/bigedp51/308fail-2.jpg

The gauge below tells you far more than a paper clip does about stretching in the web area.

http://i122.photobucket.com/albums/o254/bigedp51/IMGP5104.jpg

Please note the difference between the words "head clearance" and "headspace" and which one makes the case stretch and thin.

http://i122.photobucket.com/albums/o254/bigedp51/headspacestretch-1.gif

Fisherdave10
November 7, 2011, 05:06 AM
I'm not trying to hijack the thread, but I think there is much to learn about headspacing, head clearance and chamber dimensions.

Bigedp51, that animation is interesting. I'm not sure if you know but does the primer momentarily 'move' rearward and partially out of the primer pocket when a rifle round is fired?

I wonder because I made a newer load for 30-06 w/ 180gr bullets and a bit above the minimum charge of H4895. Oddly, the primers were slightly raised from the case head after firing. This is the first time I've ever noticed this. This occurred with my 1903 and my friend's Remington 721. Now that I think about it, the cases were still at the minimum length after I resized them like they didn't lengthen much at all from firing.

Does this mean that the load did not generate pressures high enough to cause the case to grow and push back into the bolt face 're-seating' the primer flush? Is the raised primer showing my head clearance?

I've never really thought about headspace verses head clearance.

Walkalong
November 7, 2011, 08:42 AM
Does this mean that the load did not generate pressures high enough to cause the case to grow and push back into the bolt face 're-seating' the primer flush? Is the raised primer showing my head clearance?
Yes and no. Did the case stretch a little, or none? A backed out primer shows low pressure, but after that it gets a little tricky as far as how much did the case move vs how much "headspace" is present. Again, with this method, it shows the mechanical headspace coupled with any home made clearance from an over sized case. And vice versa, did we undersize and decrease working headspace? I see a backed out primer as an indication of low pressure, but I do not try to draw any headspace conclusions from it.

With low enough pressure not to stretch the case, and if we are sure the case was all the way forward, which is should be, we can draw a conclusion from it as far as headspace/case clearance is concerned.

bigedp51
November 7, 2011, 09:27 AM
Fisherdave10

The primers back out at lower pressures and the case "headspaces" on the primer and not the base of the case. This is "normal" my 30-30 does this all the time due to is rated chamber pressure of 38,000 cup and the primers are always protruding from the rear of the case. If you make up accuracy test loads starting at the recommended starting load and work upward the primers will not be flush until the higher pressures are generated with enough to force to reseat the primers.

Also if you read your reloading manuals you are warned to "NOT" fire cases at the top pressure loadings that have been used for reduced loadings. This is due to the "reduced" load cases being "shorter" and case head separations will occur. Also each time the firing pin hits the primer on a reduced load the case gets .001 shorter from the force of the firing pin driving the shoulder to the rear as it hits shoulder of the chamber.

On my .303 British cases I put a rubber o-ring around the rim to hold the case against the bolt face to fireform my cases.

http://i122.photobucket.com/albums/o254/bigedp51/headspacestretch_frame_0001.jpg

Without the o-ring the primers would back out and the shoulder of the case would not be blown forward and not "fill" the chamber.

http://i122.photobucket.com/albums/o254/bigedp51/9-3.jpg

Below a normal chamber with approximately .004 head clearance, watch the primer "move" to meet the bolt face and then reseat as the case moves to the rear.

NOTE: The red and yellow areas are the high stress points where the brass will stretch and thin when fired to meet the bolt face. (head clearance)

http://i122.photobucket.com/albums/o254/bigedp51/deform.gif

Below a factory loaded Winchester .303 British case that has stretched .009 in a Enfield rifle that is within SAAMI headspace limits of .067.
(what happens when you fire a "thinner" commercial case in the larger military chamber, its like parking a VW Beetle in a blimp hangar.)

http://i122.photobucket.com/albums/o254/bigedp51/IMGP4523.jpg

http://i122.photobucket.com/albums/o254/bigedp51/IMGP4513.jpg

http://i122.photobucket.com/albums/o254/bigedp51/IMGP4521.jpg

Walkalong
November 7, 2011, 10:27 AM
The primer on the left is about what my .30-30 cases looked like on my first firings when I started at the low end of data. I used that, along with shoulder measurements, as an indication that I needed to size the case a bit less, and did so as I continued to work up the load.

Naturally as I closed the "headspace" down, and the pressure got up there, the cases pushed back over the primer.

brickeyee
November 7, 2011, 01:35 PM
One of the two went to the range to test fire/fire form, 6 of the first 10 cases fired had case head separation,

They screwed up the chamber.

that problem is compounded by the reloader that can not get the shoulder of the case forward with out firing it, a concept that is impossible for a reloader/fire former to grasp.

There is a way to move a shoulder forward without firing, and it is used to make obsolete brass .

You first expand the neck, then re-size it down leaving a small shoulder to hold the case in the chamber correctly.

Upon firing the remainder off the shoulder will be formed to the chamber.


It is very useful when you can only find a smaller caliber but long enough shell to reform.

bigedp51
November 7, 2011, 03:01 PM
Its called making a false shoulder and a 30-06 isn't "obsolete brass", a false shoulder can be used when fire forming any bottle neck type case. Below an exaggerated example of a false shoulder on a 30-06 case, the case will now headspace on the false mini shoulder for fireforming.

NOTE: I just quickly ran a 30-06 case into my .270 die to use as an example of a false shoulder, just to give you the idea of what it looks like.

http://i122.photobucket.com/albums/o254/bigedp51/falseshoulder.jpg

Below shows how far "off" or the difference in shoulder location between the unfired case on the left and a fired case on the right, or "WHY" you would create a false shoulder and keep the case from stretching in the web area.

http://i122.photobucket.com/albums/o254/bigedp51/IMGP7178.jpg

mstreddy
November 7, 2011, 08:23 PM
Quote Gloob
"Brass is "once fired" LC, full length resized, trimmed, and gauged with a Wilson case gauge. "

True "Once fired" LC, if military, should have had crimped primer pockets. Did you have to remove them when you reloaded your cases? Also, you mentioned being fired in machine guns, if they were fired in a M-249 SAW then they would have some issues due to the VERY loose chambers in the machine gun -- from what I have read.

There have been some posts here about mil cases fired in TRUE machine guns - M240, M249, giving grief to reloaders.

Maybe the more knowledgeable folks can weigh in?

Fisherdave10
November 7, 2011, 09:35 PM
Wow, some of you guys know a LOT. Thanks for sharing info.

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