Case Head Separation?

Status
Not open for further replies.
T

thelittlestchipmunk

Member
Joined
Jul 6, 2010
Messages
31
So today at the range I was developing some .223 loads
55 Grain FMJ
CCI 400 Small Rifle Primer
26.5 Grains Varget
2.230 COL
5.56 Brass
I was shooting once fired brass and started developing at 25 grains, then 25.5, 26, and then I went to shoot 26.5. I am using a Savage Model 25 Bolt Action. I went to fire, pulled the trigger and was hit in the face with a burst of hot gases. I did the "feel-your-face-with-your-hands-to-make-sure-nothing-was-blown-off" thing and I was fine save a little bit shaken up. I checked the gun and there was a small crack about .3 inches long that went across the area where the head met the case. My gun appears fine but I need to check it more throughly. Now my question is first, should I try this load again? Do you think it was just a bad piece of brass? 26.5, although in 5.56 brass, is a pretty light Varget load and I wasn't getting any pressure signs with the other loads. Also, I have some 27 grain loads that seem a tad bit compressed, the powder filled up to a bit above the base of the neck. Are these OK? I plan on going back tomorrow shooting some 26 grainers, then 26.5, watching for pressure signs, and then try the 27. Thanks!!
 
Case head separations are caused from excess stretching of the area just above the web of the case. A little stretch is normal, as there has to be some play so the round will chamber, and eventually the case will fail there from continuous firings.

Case head separations with once or twice fired brass is generally caused from excess headspace, whether mechanical, or artificially induced by over sizing. (Pushing the shoulder back too far.)

I would have a gunsmith check the gun for mechanical headspace. If it gets a clean bill of health, which is likely, you need to look at your sizing. A case gauge can come in handy here. Most dies will not oversize, but it can happen.
 
I'd suspect a bad piece of 5.56 brass to start with. I've bought several 1000 round batches of once fired military brass. I, carefully, visually and with the sharpened bent wire "feeler" method, feel for stretch marks or cracks in every case. I consistently find 5 to 10 cases with stretch marks or cracks in the 1000 round batch. A few would probably handle a couple more reloadings but some I feel would probably separate on the next firing.
Like mentioned, I think a case headspace gauge such as the RCBS Precision Mic or Hornady's Headspace Gauge Set which is used with your calipers is a must for setting your sizing die to only push the shoulder back a measured amount. Setting your die to push the shoulder back only two to three thousandths will extend the life of your cases and help prevent separations.
 
Most currently made FL sizing dies will not create excess headspace.
Check the inside of the brass with a paperclip to see if there's a ring inside, or cut a piece of brass in the batch in half.
Also get the rifle checked
 
http://www.chuckhawks.com/savage_25_classic.htm

“ I am using a Savage Model 25 Bolt Action “

I will never understand how case head separation sneaks up on on a reloader, the length of the chamber does not change from day to day or month to month, I will never understand why sizing a case is such a guessing game, thelittlechipmonk, if this is not the first time you have fired this rifle you should know the length of the chamber from the bolt face to the shoulder of the chamber, the first round you fired should have been measured for case length from the head of the case to it’s shoulder, and, the case should be saved and used for comparison with cases at intervals like 500, 1,000 etc,, for length and diameter.

It is not necessary to discover the length of the chamber every day but when sizing cases that fit the chamber the sizer die must be adjusted to limit sizing, again, you have a chamber, you have a die, the die has a chamber, when the die is adjusted down to the shell holder the reloader should expect cases when sized with the die adjusted to the shell holder, with an additional 1/4 turn after contact, to be sized to minimum length/full length sized and when compared to new, factory unfired cases the length of the case from the case head to shoulder should be the same length.

“Most currently made FL sizing dies will not create excess headspace”

Back to the top “I will never understand how case head separation sneaks up on a reloader...” A die adjusted to the shell holder with an additional wild guestimate of a turn can only restore a case to minimum length or as the instructions ‘instruct’, full length size. AND, everyone assumes that is what it does, except me, again it is not necessary to discover the length of the chamber everyday, but, when I size a case I want to know if my press, die and shell holder is restoring my cases to minimum length, also referred to as full length sizing, THEN! comes the tricky part, matching the length of the case to the length of the chamber (bolt face to the shoulder of the chamber and case head to shoulder of the case), none of this is possible if the reloader does not know and does not know how to measure the length of the case and or length of the chamber and does not understand how the die and chamber are related.

Again, I measure the length of the case before firing, to others that is a waste of time, I compare the fired case length with the new, factory full length sized/minimum length sized case, IF! the die adjusted to the shell holder is full length sizing, restoring to minimum length and I can measure a full length sized case and compare it with a fired case I can determine the difference in length between the two cases, the difference in length between the two cases should be the difference between a go-gage length chamber and a minimum length/full length sized case (in the perfect world).

Back to “.... dies will not create excess head space”, for most the die, press and shell holder is limited to one length, full length sizing, my dies and presses have threads, my dies are adjustable, when I want to size a case to fit my chambers I adjust the die off the shell holder, I make these adjustments with a feeler gage (back to) after determining the difference between the length of the fired case with the length of the minimum length/full length case before firing, the difference in length is in thousandths, my feeler gage has leafs of different thickness, I match the difference in length between the chamber and new, unfired, factory minimum length case then select a leaf that matches the difference, then adjust the die off the shell holder, and because of case jump back, snap back or spring back I add to the thickness of the gage, that is optional.

F. Guffey
 
now you can get all philosophical, even teary eyed about head space as to where it is, what it is and ‘what it is a reloader can do about it?’, I off sat the length of the chamber with the length of the case, the only way I have of controlling the length of the case is with a press ‘with threads’.

I can adjust the gap between the bottom of the die and top of the shell holder with a dial caliper, I can adjust the gap between the bottom of the die and top of the shell holder with a height gage. Then after making the adjustment with the dial caliper or height gage I check/verify the adjustment after securing the die to the press with the lock ring with a feeler gage, or, if I am going to use the feeler gage as a standard to verify an adjustment, why waste time with the big tools, it makes more sense to go straight to the standard, verifying transfer tool, the feeler gage.

F. Guffey
 
Bad Brass?

small crack about .3 inches long that went across the area where the head met the case.
Click to expand...
It would help to know the brand of the brass, as some is defective. See photos of 223 brass here> http://photobucket.com/KABOOOM
KABOOM
[/URL][/IMG]
KABOOM
[/URL][/IMG]
 
Last edited:
243win, yeah the crack was about a half inch higher than in that photo, in fact in looked EXACTLY like this one right here http://media.photobucket.com/image/case head separation/soupersnake/LC03caseheadseparation2.jpg
I am feeling that it was some bad brass, that brass was some that I picked up on a range, god knows what it had gone through. I will fire the load again tonight in some brass that I checked very throughly with a paper clip for case head separation. Will report back. Thanks everyone for their responses! I checked my die and it seemed to be set a little deep, ie turned about 1/2 turn vice a quarter turn down, don't know if that was the problem. I fired about ~250 rounds at this die setting and never had this happen before...
 
All I am interested in is the length of the chamber and the length of the case before and after firing.

You passed up a great opportunity when you pocked up all that brass, it is possible some of that brass was fired in a trashy Ol’ chamber that was longer than your chamber, with trashy old cases fired in trashy old chambers a reloader can adjust the die off the shell holder when sizing the cases and check for length with a gage or attempt chambering in you Savage, when the case chambers STOP, secure the die and start sizing, or use a feeler gage for control sizing by decreasing the gap between the bottom of the die and top of the shell holder, or continue trusting your luck by making wild guestimates, for me there are trusting your luck is a bad habit.

I have purchased 400 cases fired by someone else in other rifles I did not know for .08 cents each for the sole purpose of finding trashy old cases fired in trashy old chambers, to size a trashy ol’ case for most of my chambers I measure the length of the case first and then separate into groups, then determine the length of my chamber, then select a set of cases that are longer than my chamber and start sizing, I am the fan of the .002 thousands difference in length between the case and the chamber, again, that is the difference in length from the bolt face and chamber shoulder and the length of the case from the case head to the shoulder of the case.

F. Guffey
 
case head seperation.

As RC & Walkalong & (Fguffey said :D,) case head seperation.

Your photo link > View attachment 163581

[noparse]http://i7.photobucket.com/albums/y258/soupersnake/LC03caseheadseparation2.jpg[/noparse]

~
 
Last edited:
243Winxb,
case head seperation.

--------------------------------------------------------------------------------

As RC & Walkalong said, a case head separation

--------------------------------------------------------------------------------

and I said

I will never understand how case head separation sneaks up on on a reloader, ignoring the problem will not cause it to go away, me? I determine the length of the chamber first, then form cases that fit, my favorite cases for sizing cases for long chambers are trashy old cases fired in trashy old chambers, that does not mean I use trashy old cases for reloading, I could, but the #1 reason for acquiring trashy old cases is to determine the length of chambers without fire forming, again, I form first, then fire.

F. Guffey
 
I get a lot of separations in my .223 using some brass I bought used. I'm pretty it's bad brass, because out of the 1000 cases I bought, 90% were LCC with reamed pockets. Who takes the time to ream a pocket and then leaves their brass lying around? So I'm pretty sure this brass was retired for a reason (even though they pass the paper clip test). Case head separations don't seem to be a big deal in my rifle. I just extract them with the next round of ammo if necessary and keep shooting.

One thing I've noticed is my sized brass sits flush with the short end of my case gauge. I think I'll give a go at backing out the die until the cases barely fit to the long end of the gauge, next time.
 
Last edited:
Not to hijack, but can someone explain to me what causes a case head rupture? I understand the difference, and I know the cause of a case head separation, but the cause of the rupture remains a mystery to me. Is it just excessive pressure or defective brass?
 
Eldon519, the picture posted by W.E.G does not go into the category of case head rupture, there is not enough information to draw a conclusion, the case head thickness is unknown to reloaders, rifles have case head protrusion and is referred to as unsupported case head, Springfield 03 types have .090 thousandths from the bottom of the extractor groove to the case head, Mausers 98 types have .110 thousandths case head protrusion, + or – a few.

Case head protrusion: Unknown to the reloader is the thickness of the a case head. Surplus 30/06 is .200 thousandths, R-P 30/06 case head thickness is .260 + or – a few thousandths, back to the picture posted by W.E.G., the picture only gives you the information the they want you to have, based on the information not provided I will say the case believed by the poster to be a rupture is a case head separation, the case head is too thin and had that case been fired in a chamber with unsupported case head the person pulling the trigger would have experienced a catastrophic failure.

Rupture and catastrophic failure: No one measures the case head thickness, I have crushed case heads .040 thousandths, needless to say that is too much, when the case head crushed it increased in diameter, the primer pocket expanded, the primer falls out and the flash hole increased in diameter to the point my primer pocket gage falls through and if it touched on the way through it was a glance. Means nothing to anyone else but I could have crushed the case head to the point the case head thickness could have been crushed to the point the case head could have become unsupported, or the case head pressure could have exceeded the ability of the case head to support/contain. Again, that would be a rupture/catastrophic failure.

In my opinion the picture posted by W.E.G tells you what he wants you to know or think, but it has nothing to do with case head rupture.

As to testing a receiver, I have been told Springfield 03s in the early years were OK to shoot with ..175 thousandths case head protrusion, I was told by members some exceeded .175 thousandths. If that was true and the case head thickness was .200 thousandths only .025 thousands of the case head would be supported, then after head space is added and someone considers the radius on the barrel, anyhow, I have never found an 03 with that much unsupported case head.

F. Guffey
 
with a bolt gun should only be neck sized to keep from over working the brass. but you got to measure your brass and trim when too long. when your getting on the hot side of a load chrono to see where you are. its hard to see down those tiny little cases.;)
 
I will never understand how case head separation sneaks up on on a reloader, the length of the chamber does not change from day to day or month to month, I will never understand why sizing a case is such a guessing game
Click to expand...

Because the default die instructions are for full length sizing back to minimum shoulder length maybe?:banghead:
 
Status
Not open for further replies.

Similar threads

M
  • Locked
How many shots to establish a receipe?
Replies
12
Views
894
28lx
2
B
  • Locked
Can someone run a round through Quickload please?
Replies
0
Views
344
BsChoy
B
S
  • Locked
5.56 tracers? help I cant get them to work
Replies
15
Views
4K
straitnate14
S
F
  • Locked
New to reloading .223 Questions?? Help??
Replies
16
Views
1K
W.E.G.
W.E.G.
L
  • Locked
Post Your AR15 Hand-Loads
Replies
15
Views
2K
byf43
B
Back
Top