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Starline 556 case head separation

RabbitSlayer

Just had a starline 556 case head separation. I been seeing reports of this and that some have been recalled and starline replaced the people's brass. Hope I dont have a bad lot. 3rd firing. 1st was a mid book load in a factory tikka chamber. I amp annealed and did not move the shoulder and fireformed in my new 223ai barrel with a load just under book max. Again i annealed and no shoulder bump. 26.5 gr n133 53 gr vmax 7.5 primer avg 3574 24" bbl. The primers are not flat at all and brass looks perfect. I went higher when pressure testing. I have fired 56 rounds just like it. The velocity of the bad one was just 10 fps or so above average and it was touching the previous shot. I think it survived firing and came apart on extraction. Just pulled the barrel. Now i have to figure how to get the other half of the case out.

The lot is about 1.5 years old. Dang i have 250 FF pieces and 250 more loaded for my AR. I wish I had a lot number. Guess I will call starline. That will suck if i have a bad lot. Start all over...

Updated from starline:

I’ve talked to a couple of guys running 223 AI that have had similar issues. We did make a change in our brass about 9 months ago that thickened the case about .0035” at the transition in the middle of the case. How many of these do you have?



Regards,



Hunter Pilant

Process Manager

Chief Ballistician

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Your sizing too much. The bad starline brass split down the sides. Not like you show. This i what happened to mine on the first load on a brand new Criterion barrel. I doubt they will honor that brass anyway as you are not using it as what it is.

ha6q3QS.jpg
 
tommeboy said:
Your sizing too much. The bad starline brass split down the sides. Not like you show. This i what happened to mine on the first load on a brand new Criterion barrel.

ha6q3QS.jpg
Click to expand...
I am not sizing too much! I have never moved the shoulder yet! It still chambers easy, so I have not bumped the shoulder yet.

When i bump the shoulder I only bump .002 also.
 
LVLAaron said:
Maybe. yeah. Something feels weird about this. Chamber is funky, sizing die is funky.. Doesn't feel like headspace. I could be wrong.
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“I am not sizing too much! I have never moved the shoulder yet! It still chambers easy, so I have not bumped the shoulder yet.”

Can rechamber with out resizing??”

Yeah -something strange all right…
 
RabbitSlayer said:
Just had a starline 556 case head separation. I been seeing reports of this and that some have been recalled and starline replaced the people's brass. Hope I dont have a bad lot. 3rd firing. 1st was a mid book load in a factory tikka chamber. I amp annealed and did not move the shoulder and fireformed in my new 223ai barrel with a load just under book max. Again i annealed and no shoulder bump. 26.5 gr n133 53 gr vmax 7.5 primer avg 3574 24" bbl. The primers are not flat at all and brass looks perfect. I went higher when pressure testing. I have fired 56 rounds just like it. The velocity of the bad one was just 10 fps or so above average and it was touching the previous shot. I think it survived firing and came apart on extraction. Just pulled the barrel. Now i have to figure how to get the other half of the case out.

The lot is about 1.5 years old. Dang i have 250 FF pieces and 250 more loaded for my AR. I wish I had a lot number. Guess I will call starline. That will suck if i have a bad lot. Start all over...

View attachment 1649899View attachment 1649900View attachment 1649901View attachment 1649902
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That seems very high up in the body for a "head seperation"
 
I would think chamber issue since primers are round on edges but cratering at flash hole? Shoving brass into undersized off chamber.idk

I can mail you a set of dies to verify if your interested.just message me no problem just to test before going another direction
 
Not giving on opinion on the root cause of the OP's sample, but I will add a bit to explain why there is sometimes a failure where the OP's happened.

In this section view, you will see lines where there is a "facet" in the cad model. Most solid models will show a line where there is any change from one geometric surface to another, including angle changes, radius blends, etc.

On the dies that do the intermediate draw process, there is a facet line like the one in the drawing. It can be the site of a failure in a percentage of examples.


1743993041289.png

I will reiterate I don't have an opinion on the OP's brass and would need to have it in the lab to say, but just pointing out that the failure site isn't as common as the lower one, but it does happen right at that facet line in some examples.
 
RabbitSlayer said:
Just had a starline 556 case head separation. I been seeing reports of this and that some have been recalled and starline replaced the people's brass. Hope I dont have a bad lot. 3rd firing. 1st was a mid book load in a factory tikka chamber. I amp annealed and did not move the shoulder and fireformed in my new 223ai barrel with a load just under book max. Again i annealed and no shoulder bump. 26.5 gr n133 53 gr vmax 7.5 primer avg 3574 24" bbl. The primers are not flat at all and brass looks perfect. I went higher when pressure testing. I have fired 56 rounds just like it. The velocity of the bad one was just 10 fps or so above average and it was touching the previous shot. I think it survived firing and came apart on extraction. Just pulled the barrel. Now i have to figure how to get the other half of the case out.

The lot is about 1.5 years old. Dang i have 250 FF pieces and 250 more loaded for my AR. I wish I had a lot number. Guess I will call starline. That will suck if i have a bad lot. Start all over...

View attachment 1649899View attachment 1649900View attachment 1649901View attachment 1649902
Click to expand...
Is your chamber made to headspace virgin brass with .004" crush fit on closing the bolt. Or did the Smith just run a reamer in deeper to make it Ackley improved??

This matters a lot!
Post a pic of one of your formed pieces standing next to a piece of virgin brass
 
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46and2 said:
Is your chamber made to headspace virgin brass with .004" crish fit on closing the bolt. Or did the Smith just run a reamer in deeper to make it Ackley improved??

This matters a lot!
Post a pic of one of your formed pieces standing next to a piece of virgin brass
Click to expand...

Its a shouldered prefit, but it passed headspace with the gauges. My reloads and factory ammo both had a noticeable crush when closing the bolt. Ill clean the chamber really good and check it again when I out the barrel back on.
 
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