.223AI split necks on third firing (PICS)?

H

Hunt

New member
I had a .223AI built and am trying to troubleshoot an issue. I was shooting Winchester brass with a 75 gr AMAX in 26.2 gr RL-15. Upon the third firing, I had 3 of the loaded 50 split their necks.

All of the brass was fireformed with a std. .223 max load of Benchmark with 55 gr VMAX. I have not annealed the brass and am using Lee .223AI dies to full length size after each firing on f'formed.

I am feeling a crush fit when loading standard .223 ammo so I don't think it is a headspace issue. I'm also not seeing my brass grow in length.

What could be the issue here? Am I resizing too much or could I possibly have gotten some brittle brass from Winchester? I was hoping to get at least 6-10 firings before seeing something like this.

Here are the pics at varying stages of splitting:


IMG_1824.jpg


IMG_1822.jpg
 
Hunt, I made a post on 24 hr, here is some additional info.

When you size the brass with a normal sizer, it sizes the brass way down, then the expander ball enlarges the neck again. As the neck becomes work hardened, the brass will reluctantly expand...eventually, it will not expand but split instead.

Two questions come to mind, first question was the brass previously fired in a chamber that was large or is the brass new brass?

Also, you need to find out the neck dia in your chamber. you can mic the loaded round and subtract that number from the number that the gunsmith gives you off the reamer on neck dia. If you have a large neck dia, then this is the culprit.

Enquiring minds want to know...I have never heard of a 223 AI splitting necks before...yours is the first.
 
Ackley,
The brass was brand new Winchester brass that was right out of the bag. I had bought this brass from Midway a few years back and was shot the first time in the chamber as a fireform load.

As for the neck, I think it was a .249 neck and was a PTG reamer. The 'smith that built it has built several .223AIs and I've never heard anything bad....Always rave reviews. I don't think it was the 'smith in this case but rather some improperly annealed brass.

The thought has crossed my mind to dump the Lee dies and go with some Redding dies using the bushings to control the amount of neck sizing.

I'll post some pics laster.
 
For whatever this is worth, I had head separation after three reloads on 3 - Winchester Brass - 22-250 casings the other day. I have had to full length size this brass in the past because of the generous headspace my rifle has. I have now gone to only bumping the shoulders to see if the Winchester casings last any longer. I will also say I haven't been using hot loads and with the same loades, my Remington Brass ISN'T showing any problems after the same number of reloades done the same way. I kinda think its the brass.
 
Hunt, if you have a .249 neck, it is border line on a turn neck dimension.

It is not exact, but measure a fired case that has not been sized. There is some spring back in the brass after firing, so you can not accurately judge your measurement as
"exact"...it will give you some idea if you do/do not have a large neck in the chamber.

Bottom line...a quick call to the gunsmith is in order. Ask, him the dimension on the neck...it is etched right on the reamer body if he can't remember.

I have brass that I have fired in my 223 AI at least a dozen times with a .250 neck which is about .002+ loaded round dimension dia.

Yes, you are correct in springing for a bushing die for the 223 AI...will last you a life time...it is what I have been using. I think that I am using a .245/.246 neck bushing which will vary as to the thickness of the particular brand of brass that you are using. You will need a smaller bushihg for when the brass workhardenes.

After you get the bushing die, you will see an immediate difference in the amount of pressure that is needed to seat a bullet.

Let us know what you find out...I would not be surprised that your die is over working the brass. You can save that particular lot of brass by annealing with a propane torch quenching them in water.

Let us know what you find out.
 
This may not be the cause, but I had 3 new Winchester .308 cases split on the FIRST use a couple years back. New brass, mid-pressure load, in a factory Winchester rifle that's never had a split neck (before or since).
I quit buying new Winchester brass at that point.

Just FYI.
 
I would personally tried a different lot # on the Winchester or try some RP casings to see if the problem goes away.


I've been using Winchester and Lapua for my .223ai's and I've yet to split a neck.

My heavy .223ai runs Lapua casings and I have 12-13 firing on them without any issue. I've annealed once on my Lapua brass.

My light weight and g/f's .223ai both run Winchester brass. Her gun has roughly 5-6 firings on the Win brass with no problems as of yet.
 
Hunt, after looking at your brass, it is obvious that the brass is work hardened OR the annealing process at the factory was defective.

Here is what you should do to help determine possible causes.

Remove the expander ball from your sizing die and size a case that has not split...now measure that case Neck Outside Diameter...record that number.

Now size another case with the expander ball, record that number.

You should start seeing some light at the end of the tunnel at this point...don't get angry...it is what it is.
 
After looking at this some more, I took some measurements of the brass as well as taking the sizing die apart to look for anything obvious that might be causing the issue. The tolerances of the die do not seem to be out of whack and the die passed the cotton swab test as well as no visible issues being seen to the naked eye:

Fired Neck Dimensions of 5 various brass pieces:
.250
.251
.250
.250
.250

F/L Sized Dimensions with expander ball:
.246
.245
.245
.245
.245

F/L Sized Dimensions without expander ball:
.243
.243
.243
.243
.243

Lastly, the loaded dimensions of the Win. brass with a 75 gr AMAX:
.247
.247
.247
.247
.247


With that said, I'm leaning more towards this being some bad brass. It was manufactured several years ago but I do not know the lot #. I'll look at chamber later to verify nothing is wrong there but from visual inspection during cleaning, I noticed nothing.
 
I think that you have hit the nail on the head.

Annealing the rest of the brass will probably save them from the trash can.

This is one of the wierdest things I have ever seen in dealing with a bunch of different ackley calibers.

Good luck!
 
I agree about the Annealing being first thing I would do, And the Secound thing would be, Get a Redding (or whatever)Bushing Neck Die with a .246 Bushing First, You might have to have a .245 Dia Bushing but most likely will not. Your brass is being (overworked)sized .008 everytime you shoot and Load them and that could be cut in half! and probly get better performance to Boot... JMO... But has worked Great for me..
 
Quote:I agree about the Annealing being first thing I would do

It was new brass, you would kinda expect it's already annealed.
rolleyes.gif


Like I said, I quit buying new Winchester brass.
It ain't like it was cheap, either.
 
Yes it should have been! (BUT) he also said it was older New Brass, Which a couple years ago I had the same problem with a couple batchs of 204ruger Brass and you could tell when you pulled them thru the expander that something was going to give, even on the first time thru the Die.
 
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