Failures in fireforming

[nksmfamjp]

I was recently forming 7-30 Waters from 30-30 using the COW method. Why might I be getting these failures? Are the other 80 cases ok? They look ok on the outside.

Brass was once fired Winchester. All were double annealed…pre/post fl sizing to set false shoulder.

 

[Mikecr]

The brass was fired in a chamber having excessive clearance, and then if sized way back down (before your firing), it work hardened.
Brass only stretches just so far.

 

[akdad]

But if it was just the chamber why would they have done it in different spots??? Not trying to argue just want to understand.

 

[victor3ranger]

Wow

 

[victor3ranger]

I will really like to know what is going on here

 

[26Reload]

I would venture the saying 'some brass is made to reuse....some isnt'...

Look at the 4th from top...it looks like it nearly created another fissure hole at the head...

 

[nksmfamjp]

The brass was fired in a 30-30 Win of unknown origin or chamber. I'm guessing range rental somewhere.

Then I bought it when new 30-30 was unobtanium. I annealed neck and shoulder pretty good, FL sized to create a false shoulder and then annealed again. Then fireformed with 5.5gr of titegroup and COW.

Maybe I could of got 99% of the forming done at 4 gr, but I normally bump it up until I get a perfect shoulder.

I don't think the 4th down had an issue at the base, but maybe.

I guess I'm wondering what to do with the other 80. I'm going to try load development. If they keep doing this, I with toss in the trash and start over. I have the barrel coming back in a couple days and I really want to develop a load, but the brass will need to go 3 more load cycles at minimum to get through hunting season.

I will really like to know what is going on here

Me too!

 

[MagnumManiac]

Looks to be brittle brass, my 30-30 is plagued with excessive headspace, so I get 2 firings and the third sizing always ends up in head separations. I guess the tolerances in 1906 weren't the best…
Have seen this quite a bit from old hardened brass, had an entire lot of Winchester 44-40 brass crack upon firing like yours and it etched the chamber…

Cheers.

 

[Seabeeken]

Ive had a few split and always winchester. I used to hs my old 30-30 off the shoulder and brass lasted a lot longer. I sold it and the guy made a 7 waters out of it