Reloading help

[Klem]

Bigs,

With respect, forget velocities, loads and jump for a second...it's headspace. The case is too small for the chamber and when it expands on firing it exceeds the brass' ductility. Ductility means how much metal can stretch before breaking. Brass is designed to be elastic, it has to be, but it has limits.

Quick test - do as Lemonaid is suggesting and get a paperclip with a 90degree hook and rake the inside of your cases. You will feel a trench at the same spot those two cases split. Here's my very expensive tool that sits in one of the die boxes.



Get rid of the brass.

[Bigs28]

I completely understand what your saying klem and changing my routine. I was just answering other comments. I always appreciate the fast responses i get here. I learn a ton. I wish comcast was this good at solving problems.

Thank you

[Klem]

Bigs,

No worries...this is an easy fix and happens to more people than they will admit, including me. It's not dangerous because the bolt is still in battery but it can give you a bit of a shock.

If you are bumping the shoulders .003" from the spent case length then the brass is long past its use by date. Time to get a new batch and monitor the case life from now on. Sometimes it pays to buy quality brass like Lapua because if you amortize the cost of the brass over how many reloads it gives it can work out cheaper than cheap brass.

Can I ask how are you measuring the .003"? Do you have a Hornady gauge or are you using a handgun case?

[Bigs28]

Hornady b-350 in my calipers. I bought hornady American gunner and used its cases but i planned on buying lapua next. Just didn't know it would be this soon.

[Klem]

Hornady b-350 in my calipers. I bought hornady American gunner and used its cases but i planned on buying lapua next. Just didn't know it would be this soon.

Bigs,

I hear you.

Oh well, just time for a fresh batch of brass - Problem fixed.

[grayfox]

Naturally I will bow to the case separation response. Thanks Klem; Bigs what I meant by mic the brass is to use a micrometer to measure thickness of the brass at the separation point... I was thinking for the stretch/resize/fire/etc cycles, eventually the casing would thin out somewhat and then break at that point. My experience with metals is that under a cyclic fatigue the metal work hardens but in this case as well, the stretch would also thin it somewhat. I was thinking it would "thin" b/c as you resize it and stretch, you wind up also trimming some extra length -- well that brass to make up that length comes from somewhere and that would be from thinning out the casing at this breaking point.
A theory anyway.

[ported45]

Had that happen to me twice in one outing and the next thing I bought was the Hornady headspace tool.

I had previously been setting up dies to "cam over" when sizing; this is a no-no on my Hornady dies (and just imagine that it says so in the Hornady instructions!). It created excess headspace that resulted in the exact above conditions on the third firing on two pieces of Hornady brass. Do not make the mistake that all dies are to be used the same from one maker to the next!!

I used the tool to set up my sizing die to bump 0.002-0.003" and have many loadings on the same few pieces of brass from the same lot just to test the effects.

[sundowner]

You guys are right I kept this one to remind me not to over bump the shoulders . m_20200522_192233.jpg

[Klem]

Sundowner,

Yep, that's exactly the same spot for me too, only it was 223. And same as Ported it happened twice in the same batch of ammo. The front half fell out easily so I stared at it for a minute and kept firing...Boom, it happened again.

I was using a rifle gauge long before I got a set of calipers (this was years ago) so dropping all other loaded rounds into that revealed the case was lower than the Low limit - Headspace! You learn your lesson and touch wood will never happen again.

[newb]

Is that just shadowing in the pic or are the primers pierced?