.223 split neck, why?

[crest117]

Savage bolt action .223 Shooting LC once fired brass (second loading) with 68 gn. HPBT over moderate load of Varget, 24 gns. Neck split on one case, all others were fine. What would be the reason for this? Or does it sometimes just happen? Just curious as this has never occurred before.

 

[jeeptim]

Split happens

 

[ReloaderFred]

It's caused by metal fatigue, or sometimes just a flaw in the jacket material. It happens.

Hope this helps.

Fred

 

[2ndtimer]

The case also could have been fired in an AR-15 or M4 that put a deep scratch in the neck up chambering which could precipitate a split neck.

 

[243winxb]

LC skips some annealing. Standard dies over work the case neck, hardening it. Brittle brass cracks.

Fix by annealing and using bushing die.

At times, this may not even help. Defective brass. After military testing, brass is sold as scrap.. Some ammo has been placed in a solvent for age testing. It will fail early.

 

[Walkalong]

It happens, I had a batch of range brass where quite a number of them did it. Unusual for a high % to do it. Normally it is few and far between.

 

[Blue68f100]

It happens with most all brass. Anneal the brass and it should go away. I think mfg are cutting corners as mush as they can. The only need it to work once, which does not address the reloading.

 

[lightman]

One case neck splitting may be a case of "it just happens". This may have been caused by a defect that you didn't see or know about. Usually they are caused by work hardening. I've had high numbers of Winchester brass split on the first firing. Enough that I bought an annealing machine because of it.

 

[jmorris]

It happens when the brass gets hard enough the case cannot expand to fit the chamber without splitting.

It can happen as soon as the first firing.

Some cases are annealed a number of times during the forming process as well as after. With milspec ammunition, they don’t even allow them to remove the evidence of the last anneal but it’s common for the factory stuff to be shiny.

So what causes the brass to get hard? It work hardens, so taking a case that “blows out” or expands to the chamber when fired then putting it into a sizing die that squeezes it down, then dragging an expander back through the neck are all going to make it harder. How much harder depends on how much your moving it.

Take a benchrest gun, make some brass that fits the chamber, we call this “fire forming” and use a bushing that gives you .002” neck tension and you’ll get more than 20 firings without annealing them. The key is they are not moving around as much.

If none of that is an option, annealing is, I’d suggest having batches of both and good records so you’ll know if you are negatively effecting your shooting in the name of longevity.

 

[Casefull]

It also happens a lot when the Oal of the case is too long. Military brass is crimped and usually needs to be shortened after the first firing. Once I started paying attention to this I had a lot less split necks. May not be ops problem.