Brass Failure 223AI

[xswanted]

Hi guys,

I just set up my first remage barrel. I have a pre fit Douglas 7 twist chambered in 223AI

I used a go gauge to set headspace.

While fireforming brass I had 6/40 that would not fire. In my past experiences with ackley type cases this isn’t totally out of the ordinary. Fireformed cases fired and chambered fine.

The picture of the case here was on its first firing as an “improved” case (2nd loading of the brass total) and it broke apart when extracted.

There was nothing on the shot that indicated brass had been compromised and even the group wasn’t effected. Speed was consistent with the prior two firings. The load used was below max according to the manual used.

I removed the remainder of the case and fired 6 more shots with no issues.

The rest of my brass looks good, no indicators of any cracking or a line around the body where this one broke.

Was this just an unfortunate piece of brass or could this have been caused my excessive head space?

I took the barrel off, rechecked and put it back on already. It seems it’s inline to where it needs to be.

Thoughts?

 

[Plumsask]

When I headspaced my 6 Ackley I noticed after using go gages that some brass would crush fit and others would not. There was a huge variance in brass tolerances. I ended up setting headspace below minimum to ensure crushed and I had my shell holder machined down .010 to allow me to bump the shoulder back. Hope this helps.

 

[xswanted]

When I headspaced my 6 Ackley I noticed after using go gages that some brass would crush fit and others would not. There was a huge variance in brass tolerances. I ended up setting headspace below minimum to ensure crushed and I had my shell holder machined down .010 to allow me to bump the shoulder back. Hope this helps.

Agreed, I measured cases quite carefully after this and that is what led to resetting the headspace on this rifle. I believe I may have been slightly excessive and set it up as you described, below minimum.

 

[Plumsask]

Possibly a piece of brass that was short from factory from the head to shoulder.

 

[Ramblerman]

You have an Ackley go gauge? Ackley is about a .004" crush fit on a SAAMI sized 223 case...if you are using a standard 223 go gauge and with any positive headspace (Slop) in there, you are gonna have happen what just happened. The only thing a standard go gauge is good for is a no go gage in an AI.

 

[243winxb]

I used a go gauge to set headspace

Was it a 223 Remington Ackley Improved 40-Degree Shoulder gauge or a reqular 223 or 5.56 gauge.

The case separation is from stretching, at some time in the cases life.
A 223 in a 5.56 chamber with .014" head clearance will separate just like your photo. May take more then 1 firing.

I had brass separate on fl sizing also.

Cheap factory ammo brass may have skipped 1 or 2 Annealings in the manufacturing process.

Seems i type slow.

 

[Cemetery21]

If you only have 40 rounds, pretty easy to use a straightened paperclip to feel for a stretch groove inside the case. I had to sort 1400 when I figured out I was setting the shoulder back too far. No failures since I got my method sorted.

 

[xswanted]

Thanks guys, the go gauge is for the 223AI

 

[jepp2]

While fireforming brass I had 6/40 that would not fire.

This is your first indication your headspace is excessive.

I bought a used 223AI. Asked if the barrel was set back when it was converted, seller didn't know. I took my brass collection of various lengths case head to datum, and none had any contact. So I sized some once fired cases without setting the shoulder back, and while none failed as yours did, several showed the incipient case head separation marks. And I picked the ones that were the longest.

The barrel markings were still lined up, so I knew it had been chambered without setting the barrel back a turn. I sent it to my smith. Headspace for the 223AI as mentioned is supposed to be -0.004". Mine was +0.016. Or 0.020" excessive headspace. My smith chambered it properly and corrected the problem.

 

[B23]

I just set up my first remage barrel. I have a pre fit Douglas 7 twist chambered in 223AI

I used a go gauge to set headspace.

Did you use both a go AND no go gauge, or just a go gauge?

 

[Uncle Ed]

The picture of the case here was on its first firing as an “improved” case (2nd loading of the brass total) and it broke apart when extracted.

Thoughts?

Was the first firing of this case done in a standard .223 chamber?

It is possible to raise the die and make the case longer than the chamber like in the image below.

Then adjust the die downward until the case chambers with slight resistance on bolt closing.

I buy bulk once fired military Lake City 5.56 brass and some of the cases have to be sized more than once to get the shoulder pushed back far enough.

The Redding competition shell holders tell you to start with the +10 shell holder and work down with the smaller shell holders until the case chambers. Meaning you could do the same thing using feeler gauges between the die and shell holder.

Below the air gap between the die and shell holder should make the case longer than the chamber. And you just keep using thinner feeler gauge downward die adjustments until the case chambers.

 

[STOMP442]

When fireforming Ackleys I always make sure I have a bullet seated long with at least a 10 thou jam to ensure the case is held tight in the chamber and against the bolt face. I generally use a medium charge of powder and never had a problem.

 

[shoot4fun]

You say headspace was checked with a go-gauge. I see nothing about a no-go. Many don't use no-go and just tape the go-gauge for comparison.
Did you do that? I've had, in spite of my best effort to control it, barrels turn just enough when tightening that they headspace got over the max when it was rechecked.

 

[Deleted old_dood]

I was the OP in this thread with a problem similar to yours http://forum.accurateshooter.com/threads/lesson-learned-primer-pockets.3956625/

while I originally thought the misfires were due to the primer pockets, I feel that actually they were more related to using CCI 450 primers which have a harder cup. Subsequent fireforming of the same brass, without doing anything to the pockets, using CCI 400 primers, resulted in no misfires.

 

[xswanted]

Did you use both a go AND no go gauge, or just a go gauge?

I used the "tape" method on the go gauge and it would not close.

 

[xswanted]

Was the first firing of this case done in a standard .223 chamber?

It is possible to raise the die and make the case longer than the chamber like in the image below.

Then adjust the die downward until the case chambers with slight resistance on bolt closing.

I buy bulk once fired military Lake City 5.56 brass and some of the cases have to be sized more than once to get the shoulder pushed back far enough.

The Redding competition shell holders tell you to start with the +10 shell holder and work down with the smaller shell holders until the case chambers. Meaning you could do the same thing using feeler gauges between the die and shell holder.

Below the air gap between the die and shell holder should make the case longer than the chamber. And you just keep using thinner feeler gauge downward die adjustments until the case chambers.

This is pretty interesting thank you!

The first firing on this brass was done in the 223AI while fireforming.

 

[xswanted]

I believe, that while I tightened the nut down, something moved on me and it was my own negligence for not re checking the go gauge at that point.

I corrected the, what I believe to be excessive headspace, and fired 15 shots yesterday doing some load development. No issues and no funny looking brass.

I will plug Douglas Pre Fit barrels as well.....this gun flat out shoots.

 

[Ackman]

Hi guys,

I just set up my first remage barrel. I have a pre fit Douglas 7 twist chambered in 223AI

I used a go gauge to set headspace.

While fireforming brass I had 6/40 that would not fire. In my past experiences with ackley type cases this isn’t totally out of the ordinary. Fireformed cases fired and chambered fine.

The picture of the case here was on its first firing as an “improved” case (2nd loading of the brass total) and it broke apart when extracted.

There was nothing on the shot that indicated brass had been compromised and even the group wasn’t effected. Speed was consistent with the prior two firings. The load used was below max according to the manual used.

I removed the remainder of the case and fired 6 more shots with no issues.

The rest of my brass looks good, no indicators of any cracking or a line around the body where this one broke.

Was this just an unfortunate piece of brass or could this have been caused my excessive head space?

I took the barrel off, rechecked and put it back on already. It seems it’s inline to where it needs to be.

Thoughts?

 

[Ackman]

First forget the go gauge, don't use it. Worthless. You don't mention what brass you're using, but no matter which headstamp, .223 brass in one box can vary more than the .004" that people throw around for a "crush" number. And the difference between the longest of one headstamp and the shortest of another can easily be twice that amount. I'm talking about the measurement from casehead to base of neck..... on initial firing an AI headspaces on the neck/shoulder junction. With a remage nut, set your headspace off several different pieces of brass. The amount of felt bolt pressure will vary slightly from case to case. With a .223 case even what would seem like a lot of "crush" won't have much felt bolt pressure. Set it so you feel definite resistance when closing the bolt. You'll get a perfect case every time and those things will shoot just as accurately, and faster, than the standard .223. BTW - my .223AI's are chambered for .011" - .015" crush on IMI brass. It's not too much, works beautifully.