.243 Split Necks

[Darryll]

I loaded 50 pieces of new Winchester brand .243 brass and everyone of the necks split. I have loaded other calibers, some with great sucess but this one has me stumped. I'm afraid to fire the other 50 rounds that I have loaded. I full length sized the brass with a new Hornady die set. The splits run from just above the intersection of the shoulder and neck to just below the top of the case. I used load data from a reloading manual, with the formula for the components that it recommended. Any suggetions would be greatly appreciated.
Darryll

 

[lpreddick]

i once had this problem. if you gun is factory the neck portion of it's chamber could be .004 or larger in diameter than the loaded round. the brass has to stretch to it's diameter. if your brass is old or used a lot it could also be work hardened and somewhat brittle and would benefit from annealing. a custom chambering with minimal neck clearance results in very little neck splits, esp if you anneal. measure a fired round and add .001 which gives you a measure of your neck diameter. since i only shoot custom i haven't had a split neck in...?

 

[boltgunluvr]

Darryll....did they split while sizing or after you fired them? I've used Win brass for many years and never any issues. Bullet, powder, powder charge, primer, etc??? By any chance did you size a little too much? 243 Win is an overbore cartridge so it will do better and remain less volatile with slower powders. Let me know.

 

[7x57]

I can't say for sure about the .243 dies, but I have the Hornady dies for .223, and it definitely sizes the body of the case down to minimum spec, i.e. small base dies fashion, and the neck is aggressively sized down by the die and then back up by the button. Certainly much more working of the case compared to RCBS, Forster, or Redding dies that I have. If the .243 dies work the neck as much as my Hornady .223 dies do, then I could see why the necks are splitting prematurely. New brass should be fairly malleable not split. Lube up the inside and outside of the neck. Hope that helps.

 

[BoydAllen]

Defective brass..contact Winchester. I would email with attached pictures, after making phone contact and finding out who to send it to.

 

[fredhorace77]

is this the first time you've ever loaded for this gun? could there possibly be something in the neck area of the chamber that the brass is swelling against and causing it to split.

 

[223Rem]

New brass and split necks=bad batch of brass.

Pull the bullets from the unfired rounds and return all of it (once fired stuff too) to the MFG and ask for replacements from a difference lot.

Necks should not split upon the first firing, unless there is something seriously wrong with the chamber. Brass is very malleable and that is why fire-forming and necking up/down is feasible.

In the meantime, buy the cheapest factory loads you can find and shoot them. Borrow five from a buddy if you have to. If the brass is OK or not, you will know either way where your problem lies.

 

[Darryll]

Thanks for all your remarks. The brass I used didn't split until it was fired, and I didn't use any lube for inside of the neck, but I will next time. I have purchased an RCBS die set as well. I've fired factory ammo with no issues either.
Darryll

 

[243winxb]

Use Bushing dies.

Over worked brass splits. But new brass should not on the first firing. Lubing the inside of the neck, may make a difference.

 

[Brians356]

<bump>

In working up loads for a 6mm Rem, I have suddenly developed two splits in a single case neck out of a set of 50 cases. The splits are oriented longitudinally, roughly in parallel, and do not extend to the case mouth.

Brass are Remington which have been fired and neck sized 5 times using a Redding bushing neck die. The necks are unturned, chamber is a factory R-700 from the 1970s. Fired case ODs measure about .004" larger than loaded ones, and the neck bushing is .002" smaller than loaded.

I see no evidence of stress or incipient cracking in any of the 49 other cases (after polishing necks with 0000 steel wool and inspecting under magnification.)

I do recall seeing one case with at least one impressed longitudinal furrow in the neck which was apparently caused by foreign material in the neck of chamber. After cleaning the chamber and reloading and firing the lot of brass again, I believe the crack might have developed where the furrow had been imprinted in that case. Since I didn't take pains to track that particular case, however, I cannot be certain that's what happened. The theory would be that the neck was weakened by the impression. Any relevant comments appreciated.

My inclination now is to anneal the necks just out of prudence. Obviously there has been some work hardening after 5 firings.

 

[CaptainMal]

Surely you measured the outside of the necks on the fired cases. Compared to the outside of the necks on the loaded rounds, how much larger is it?

If it's a chamber problem that should tell you instantly. If it's only a few thousandths or so, it's a brass problem. If so, then annealing might be a solution or ...

 

[Brians356]

Surely you measured the outside of the necks on the fired cases. Compared to the outside of the necks on the loaded rounds, how much larger is it?

I previously wrote: "Fired case ODs measure about .004" larger than loaded ones, and the neck bushing is .002" smaller than loaded."

 

[Joe R]

Darryll said: I loaded 50 pieces of new Winchester brand .243 brass and everyone of the necks split. I have loaded other calibers, some with great sucess but this one has me stumped. I'm afraid to fire the other 50 rounds that I have loaded. I full length sized the brass with a new Hornady die set. The splits run from just above the intersection of the shoulder and neck to just below the top of the case. I used load data from a reloading manual, with the formula for the components that it recommended. Any suggetions would be greatly appreciated.
Darryll

Darryll,
It is my opinion that the biggest problem you have with reloading the .243 is the Hornady dies. When I first started reloading (4 years ago) I started with a Hornady die set, I had nothing but problems with them. I understand the attraction (they are inexpensive). After a lot of frustration I bought some Redding dies, like 243winxb shows, and never looked back. You may have other issues as well (read the article below it explains the causes of necks splitting) but my experience with Hornady New Dimension dies was horrible.

Good luck

 

[sbhooper]

Surely you measured the outside of the necks on the fired cases. Compared to the outside of the necks on the loaded rounds, how much larger is it?

If it's a chamber problem that should tell you instantly. If it's only a few thousandths or so, it's a brass problem. If so, then annealing might be a solution or ...

I have had case necks split on 6mm cases, but usually after a number of reloadings. It tells me the brass needs to go into the recycle can. I have had no issues with newer brass.

 

[searcher]

I have a pal that when new to reloading, he had the same issue you are having. Every single handload split - no matter the powder, bullet, primer, etc. I was puzzled as you are. I found after measuring the 'HEADSPACE" of his loaded ammo, he was pushing his shoulders so far back that part of the neck was in the chamber when they fired - guaranteeing a split (not to mention terrible accuracy and an occasional misfire). If you have a Hornady headspace measuring device (or similar) - compare a factory round with your reload. Normally, I would say compare with a fired case - but when cases get pushed so far back - it can take more than one firing to get them pushed back to where they should be in the absence of jambing the bullets. This sounds to me like a simple die adjustment problem.

 

[bheadboy]

in my experience split necks come from one/or both of two problems

THe brass needs annealing - and this can be new as well as multi fired

the chamber neck - die neck sized prior to expansion is too great and the expansion button expands it back, too much metal flex.

two things, take the fired case, measure the neck, size without the expander button and measure the neck, then size it with the expander and measure, also measure the expander button dia. it should not be more than .002-3 below bullet dia.


if there is more than .002-3 thou expansion, I would think the die is over sizing the neck area, the loaded round neck dia should not be more than .003-4 less than the fired case measurement.

just my thoughts others may disagree.

Bob

 

[snowshoe]

Case length can also cause split necks in addition to serious pressure increases if cases are too long. The case neck is crammed into the chamber throat and no place to expand. Cases can sometimes grow a lot quicker than you would think with new brass. I've seen this happen with both .220 swift and 8mm Mag cases.