Case head seperated?

A

avd

Sergeant
Full Member
Minuteman
Jan 9, 2010
120
0
53
ho, tx
#1
I was working up a load for my TC Encore in .308. The bullets are Nosler Balistic Tip, 175gr. The powder is IMR 4064. I shot five rounds with 41 gr, five rounds with 41.5 gr, 10 rounds with 42 gr and 2 rounds with 42.5 gr. The third round of 42.5 gr is when the case head seperated from the shell.

Everything else about all cases looked normal to me. Is this a sign of over pressure? Could it be fatigue from multiple reloads?

Thanks for any input.

avd

DSCN0116.jpg
 
#2
Re: Case head seperated?

most likely fatigue from multiple loads, how many cycles did you run that brass. Overpressue usually will split the case, in some cases it can do that but your charges are in the normal range. So my guess is just fatigue.
 
#3
Re: Case head seperated?

looking back through my reloading log book, i think there are or four to five reloadings on this batch of brass. Apparently that is too many?
 
#4
Re: Case head seperated?

Things were going pretty well up until then. How do i get the case out of the barrel? I have not tried to get it out yet. Is it going to be stuck or will come right out?

DSCN0117.jpg
 
#5
Re: Case head seperated?

what kind of brass? My Lapua brass i had 24 reloads before I started to get similar results. But it was at a match. I'd shot my 5 sighters and started to shoot my first string and I made it to the 8th or 9th round and had it separate. It was a 308 also. after that I bought new brass.

Use a dental pick and check for case head separation. if you have it, i'll be a little bumb that the pick catches on.

xdeano
 
#6
Re: Case head seperated?

to get the rest of the shell out of the chamber, put a cleaning rod into the muzzle end and screw a larger brush on your cleaning rod, and pull it back up through the chamber until you know that you are in contact with the case neck then give it a good pop with the palm of your hand and it should just pop right out. I've had it with a coworkers gun that i couldn't get it out. If in doubt take it to a smith.

xdeano
 
#7
Re: Case head seperated?

"Frontier" is stamped on the bottom. I am not sure where i got this brass. I think this brass came from some factory ammo i shot some time ago.
 
#9
Re: Case head seperated?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: avd</div><div class="ubbcode-body">"Frontier" is stamped on the bottom. I am not sure where i got this brass. I think this brass came from some factory ammo i shot some time ago. </div></div>

FWIW, Frontier was factory ammo from Hornady. Been a while since I have seen it. It's all just Hornady now <span style="font-weight: bold"><span style="color: #FF0000">I think</span></span>.
 
#11
Re: Case head seperated?

Do you have the tools to measure how much you are bumping the shoulder? Bumping the shoulder more than .0025" (two and a half thousandths) will cause the case to stretch down near the case head. Brass will normally flow fron the area near the case head toward the shoulder area. That's where the "dreaded donut" comes from.

If you have other brass in this loading batch I would seriously check the insides with either a dental pick or a bent wire with a small sharp hook on the end. By putting the wire all the way to the web of the case head and easily pulling it out, it will most times hook on the makings of a crack. I usually check each case in 1/4 turns at a time. That actually helps in catching the cracks before they seperate. When the cases have inside cracks like that, put it in the scrap box. Or use it for length dummys or other set up.
 
#14
Re: Case head seperated?

The rest of the case slid right out with the help of a dental pick.

I do not have the tools or the know how to measure how much i am bumping the shoulder. i've only recently started loading .308, maybe i do not have the die set up right. I am using rcbs stuff and set the die up per the instructions. I will take a dental pick and see if any of my other cases from today have cracks in them. I will look around on the net as well and see what i can find on setting up the die.

Thanks for all the help.
 
#15
Re: Case head seperated?

Measure your fired cases .200" up from rim. Should be .471-.473".
Size your cases as normal and remeasure same area and tell us what you have? I suspect you will have .468-.469.

Measure a new case unfired, it should be .465 for commercial brass.
 
#16
Re: Case head seperated?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: avd</div><div class="ubbcode-body">The rest of the case slid right out with the help of a dental pick.

I do not have the tools or the know how to measure how much i am bumping the shoulder. i've only recently started loading .308, maybe i do not have the die set up right. I am using rcbs stuff and set the die up per the instructions. I will take a dental pick and see if any of my other cases from today have cracks in them. I will look around on the net as well and see what i can find on setting up the die.

Thanks for all the help. </div></div>

PM sent.
 
#17
Re: Case head seperated?

Your problem has come from oversizing your cases and the stretching that results. This stretch only has to happen once and the case will fail prematurely . Or a chamber that is too deep.
You are obviously a good shot but maybe your die setup needs some work .
This is a problem with the TC encore the type of action does not help you feel the right case fit like a bolt action will.
Also modern rimless ammo is prone to this problem as older rimmed ammo would just blow the shoulder forward and take up the space with out stretching back at all.
You have to work out what kind of fit you have with new unfired cases . So you can see if the chamber is too deep or if you are oversizing and pushing the shoulder back as others have said.
If you are oversizng then maybe a change in die systems might help you get a better case fit.
If the chamber is too deep then you are going to need to expand the case necks up and then size down part of the neck length to form a second small shoulder . You need just enough second shoulder to create a slight jam fit in the chamber for the first fireforming shot.
This will blow the shoulder forward not stretch the case back.
After that normal loading can be used and normal case life will result.
 
#18
Re: Case head seperated?

I appreciate all the help. I am going to do some reading and try some of these suggestions. I will keep everyone posted.

My TC Encore has been to say the least problematic. I shoot the exact same rounds in my Howa with no issues that i know of and the groupings are pretty good.

DSCN0027.jpg
 
#19
Re: Case head seperated?

I had the same situation with some 50 cal brass.I sized them to a match rifle chamber and then shot some out of my AR50 rifle.Alot of kroil + a 3/8" pipe nipple extractor and a breaker bar got it out.
Your going to have to resize the brass by turning the sizeing die in,in small increments till it'll chamber in your encore.This brass should only be fired out of your encore.I would then buy another manufacturers brass and have it sized for use only in your howa.That way you'll be less likely to have this problem occur in the future.Been there,done that.Luckily it was at the range and not in the field.
STEVE
 
#22
Re: Case head seperated?

Mike Bellm was gracious enough to help me with my encore. At first , the gun would only fire about half the time. Then when it did fire, by the seventh shot i was off the bottom of the target. I corrected head space, put stiffer springs in the hammer and the lock up mechanism, and a lighter spring in the trigger. I also had to change the forearm from a synthetic stock to a piller mounted wood forearm. And i cant remember what else. I bought the gun new. I called and emailed TC and got no response. So i found Mike Bellm on the net and began working on the gun myself. I am finally getting decent groups and the trigger is really nice now. However the gun should have functioned well when i bought it. Recently i bought my howa for half the price and it shoots great right out of the box. The howa was meant to be a deer stand/pig gun. It still will be but i have sent it off to short action customs for a few things. Cant wait to get it back.
 
#23
Re: Case head seperated?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hummer</div><div class="ubbcode-body">Measure your fired cases .200" up from rim. Should be .471-.473".
Size your cases as normal and remeasure same area and tell us what you have? I suspect you will have .468-.469.

Measure a new case unfired, it should be .465 for commercial brass.
</div></div>

I got .469" on my fired brass. .465 on my unfired brass and .465 on a new factory round.
 
#24
Re: Case head seperated?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hummer</div><div class="ubbcode-body">Good info there. I only have one barrel for TC and it is 6.5 TCU and I have been lucky with no problems but I can readily see problems with rimmed ammo. Thanks for that http. </div></div>
In my opinion Rimmed ammo will work better in a break action , thats what they were originaly designed for.
If the rim is correctly head spaced then the depth of the chamber at the shoulder is not a dangerous issue as long as its close the case will blow forward if its a bit short.
Its not possible to creat a dangerous headspace situation by sizing like you can with a rimless round when the round is headspaced by a rim and not a shoulder .
Thats why rimmed cases can have No shoulder at all . They do work better with little or no shoulder.
I have a 30-30 and it never causes any issues . However you do have to make sure the rim recess in the chamber is kept clean.

 
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