How to prevent case head separation

[Idaho]

I shoot a Model 10 .223 and use Lake City and Lapua brass. My load is CCI-450 primers, 24 1/2 gr of CFE223 pushing a 75gr A-Max. I use Redding Type-S match dies with a .244 collar and bump the shoulder back no more that 4 thousandths measured with a Hornady headspace gauge.

My LC brass started experiencing case head separations on a regular basis and I quickly discovered the bright ring above the base of the case as the tell tale sign. (by the way, I now carry a short piece of cleaning rod and a brass bore brush to remove the half of the case left in the chamber)

Thinking that the problem was the LC brass I bought some Lapua match brass and after only three firings I noted the dreaded bright ring at the base of a few cases. Drat.....

Research online has not been much help. Advice on how to prevent case head separation is basically watch for the line, feel the inside of the case with a paper clip and throw the case away.

Some guys on here claim to get 20 or 30 firings from cases without any failures. I suspect that I'm doing something wrong with my FL sizing die but can't seem to nail it down. Any constructive advice will be appreciated.

[Robinhood]

You are over sizing your brass. Check barrel chamber head space before going forward.

Cave man method. (you gotta start somewhere)
Back off on the die a half turn. Size a piece of fired brass and test. Do this until the bolt closes turning very small amounts. A little is a lot here as one complete turn of the die is about .072".

Marksman method.

Get a case gauge and size to fit Like a Lyman or L E Wilson.

http://www.milsurps.com/images/imported/2009/12/IMGP6321-1.jpg

RCBS Micrometer case gauge
https://images-na.ssl-images-amazon.com/images/I/41hUq1oERPL._SX355_.jpg



Hornady LnL Case Head Space Gauge (requires a dial caliper with good resolution on the dial like .100 per rev.)
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQ2ZxSWhcgpwbPTMc3owESvPOt-98JOS5tXUH6EQ14aXxyuoYA1IQ

Sinclair's (HH nut) Case Comparitor
http://www.brownells.com/userdocs/products/p_749002942_1.jpg

[Idaho]

Thanks. I use the Hornady headspace gauge but will take your advice and back off the die a little to see if that ends the failures. I'm also going to take a sampling of my brass and the gauge and my caliper to my gunsmith to get his opinion.

[Robinhood]

Do you compare your fired brass to your sized brass?

[Mozella]

Here's a tip you might tuck into your memory bank.

I've had a few case head separations caused by using my plinking brass nearly forever. Usually the primer pockets wear out first. And always before, the two parts have simply fallen out of the chamber. But a few weeks ago one case broke and the forward part was well and truly stuck. It was a brand new barrel and I had not polished the chamber, but I certainly did after I got the stuck case out.

The usual methods failed including using two different mechanical case extractors.

So I plugged the bore just ahead of the case, melted some chamber casting metal with my heat gun, and poured the molten bismuth into the chamber. I waited one minute and then tapped the casting out, along with the broken case, using a rod up the muzzle. Not something you'd do at the range, but effective and safe for your chamber. Don't spill any molten metal on your foot.

[The Old Coach]

Could your rifle need adjustment of the headspace? Wouldn't be the first one.

"Over-sizing brass". I'm going back 20 years or more here - - I remember that some .308 dies were designed to "small-base" the brass to make semi-autos more reliable. Is it possible that the dies you have are doing this? Measure a sized case 3/8 inch up from the base, and compare to a fired case.

Put an empty but primed case in the gun and fire the primer. The real caveman way of checking for excess headspace. The primer will back out by exactly the amount of headspace you have. Pistol primers work better for this trick.

Personally, in a bolt gun I consider .004" shoulder setback to be quite a lot. I try not to set 'em back at all, until the bolt starts closing hard.

[m12lrs]

You are bumping the shoulder .004? On a bolt.gun you should bump 1 to 2 thousands. If it were an AR then 4 thousands is about right. You are measuring your fired brass and bumping the shoulder from there right. Don't think that is your.problem though. Even if you had the die all the way down to the shell holder this shouldn't be happening with 3 firings.

Probably a headspace problem. Check with a set of go/no go gauges. What is the difference between unfired brass and your fired brass

Doesn't look like.an excessively hot.load. are your primer pockets loose?

[243LPR]

Is that die a full length die? If so I'd get a collet die and size just the neck and not worry about bumping the shoulder until they become harder to chamber.

[Steelhead]

I'm curious as to how much the case is getting blown out on first firing?
I also agree on .001 to .002 of shoulder setback.

[Idaho]

Your replies and a visit with my gunsmith gave me a course of action. You are correct, I was bumping the shoulder back too much. The gunsmith also recommended neck sizing only so I ordered a Redding bushing neck die.

While I was waiting for the shop to open this morning to get in to see the gunsmith I measure the diameter of two loaded Lapua cases and was shocked! I started out reloading the 223 with a bunch of misc brass and then bought a few hundred cases of once fired LC brass. When I ordered the set of Redding S-Type dies I measured the diameter of loaded cases and subtracted 0.003" and ordered a .244 bushing. Today I discovered that the Lapua cases measured .250". I had .006" of neck tension. Not only am I bumping the shoulder too far but I'm also working the case neck too hard. I imagine that forcing the expanded neck down to .244" and then forcing a 75gr A-Max deep into the neck is pushing the neck and shoulder down. That means there will be excessive headspace in the chamber. I've now ordered three more bushings including a .248" and a .249" along with some new case lube.

It will take a few weeks for me to know if this solves the problem because I have to wait for the new die and bushings to arrive and then shoot and reload a few more times.
The rifle has been very accurate even with the abused cases and excessive neck tension so I may also see an improvement in the accuracy with the new die and bushings.

I will let you all know.

Thanks for the advice.

[m12lrs]

So you feel you were.collapsing the shoulder when seating you bullets? That certainly would cause problems. Do you still have any of those loaded rounds you can check? Simply use your headspace gauge on a resized.case.and a loaded round

[Idaho]

So you feel you were.collapsing the shoulder when seating you bullets? That certainly would cause problems. Do you still have any of those loaded rounds you can check? Simply use your headspace gauge on a resized.case.and a loaded round

No, None of the necks collapsed. I'm just assuming that as tight as the bullet fit into the neck that it had to put undue downward pressure that could have set the neck and shoulder back a bit. I have a headspace gauge that I set up the FL die with but I don't recall ever measuring a loaded round to see if there is any difference. I will check that out.

[Robinhood]

Idaho, I'm sorry about my post. Like I often do I only read part of the post.


I'm just assuming that as tight as the bullet fit into the neck that it had to put undue downward pressure that could have set the neck and shoulder back a bit.

I would be careful with the size of bushing I was using. Besides the bullet being overly tight in the neck you are likely inducing run-out on your loaded ammo...to an unacceptable level.

[RC20]

Bench rest is moving or has moved to FLA dies and minimal bump back.

You will need to anneal the neck and shoulder fairly soon to avoid neck splits.

tough one, best is the Annie but that's a trendy puppy. I get to use my brothers so am fortunate there.

Most use torch setup, very difficult to ensure temp compliance.

[m12lrs]

annealing is a very important part of brass life and controlling neck tension. I anneal every three firings. My super accurate long range stuff gets annealed every firing. If it isn't done right it is less than worthless. You can feel the difference when you seat bullets in properly annealed brass.

I use this annealer . you can add on the annie but it is a pretty pricey upgrade. I agree it is hard to do it right and consistently by hand. You need to use tempaq and a consistent method. I can set the annealer up with 100 cases or more and start another project just keeping an I on it.


https://youtu.be/tCWni2nNNeE

[yobuck]

You don't appear unwilling to part with cash in order to get what your striving for. Which can certainly be a good thing.
I would recomend everybody carry a cleaning rod with bronze brushes, especially when hunting if at all possible.
But in a pinch, a green branch whittled to fit hard thru the case from the action end has been known to work.
As for the problem your having, it could be your overworking the brass, but changing your setup should tell you that.
Ive had head separation, but only on large capacity magnums with several firings on the brass. In fact I will no longer use
magnum brass fired more than 1 time for hunting, as I just wont chance a case failure. And I also try every round thru the gun.
We are talking about a standard factory rifle here, and id be curious as to just how much better it shoots using the dies
you've chosen, as opposed to just using standard say RCBS full length dies set up like the directions say to do it.
Just for kicks, separate some brass and either borrow or go on ebay and buy a set and find out if your problem goes away.
Annealing, and neck tension are unrelated as to the issue of head separation in my opinion.
You could also just get or borrow a sizing die and use the seater you have

[Idaho]

yobuck, I appreciate your thoughts. I have 100 new Lapua cases that I had prepped and primed. Part of the preparation was for me to run them through the case neck sizing die to get consistent neck tension. (I now know that was waaaayy too much) Tonight I dug out the size button for the decaping rod and lubed the inside of the necks and ran then all past that button in the die. Then I loaded up 10 cases and am amazed at how much easier the bullets seated. (one of the new collars that I ordered for the neck sizing die will duplicate this effort)

Now, I can't wait to get to the range to see if it makes any appreciable difference in MV spread and accuracy. I like puzzles. Mostly, I like chasing the secret to extreme accuracy. It still elludes me but I'm getting closer and having a blast along the way.

As to annealing the cases, I agree, I don't think it will help appreciably in my case. (no pun intended) Anyway, the new Lapua brass is clearly annealed and ready to go.

[yobuck]

Some day when you can spare some time, take a ride to Gillette Wy. Take rt 59 south thru town about 5 miles to Hoe creek rd and turn right.
About 2 miles will bring you to Macs Gunworks on the right. Chuck Macintosh is the owner/gunsmith. He also has a range there where you canshoot at steel targets at 100 yd intervels out to 2000 yds.
He is a very easy guy to meet and get to know. He would no doubt let you shoot one of his guns.
Probably even one of his long range pistols.
You will find that good guns shoot, and they will shoot well for everybody with pretty much whatever you feed them.

[Wide Glide]

Probably would have been cheaper and harder to screw up if you bought the lee collet neck sizer and redding body die. No messing around with bushings or neck tuning just simply neck size fired brass with the lee each time until they start getting tight to close the bolt on then use the redding die to bump shoulder back along with neck sizing with the lee.

[Idaho]

Probably would have been cheaper and harder to screw up if you bought the lee collet neck sizer and redding body die. No messing around with bushings or neck tuning just simply neck size fired brass with the lee each time until they start getting tight to close the bolt on then use the redding die to bump shoulder back along with neck sizing with the lee.

Yes, well, live and learn. I'm enjoying the journey, learning a lot, looking forward to each revelation.