What causes this?

[Gene]

I have heard too many bad stories about Hornady brass, and never buy it. I suspect some factory defect.

DO NOT attempt to anneal any brass lower than the neck-shoulder junction.

Have you tried other brass in this rifle and what was the result?

 

[just country]

morning, I had this happen with a 257AI. same case. I was using Winchester brass.

these were reloads. had been fire formed. was testing loads. had head separations

and cracked cases. threw all of the reformed cases away. started with new brass.

never did find out the cause. a person asked if loaded brass should b stored, these

these cases had been stored?? this was a new barrel installed. lightbulbgun)

 

[Laelkhunter]

Any chance to try the loaded rounds in a different rifle to see if they split in the other rifle too?

 

[LRSickle]

I have heard too many bad stories about Hornady brass, and never buy it. I suspect some factory defect.

DO NOT attempt to anneal any brass lower than the neck-shoulder junction.

Have you tried other brass in this rifle and what was the result?

I've been shooting Win and Rem brass in this gun since 2008. I've never had a problem with either. My regular load is 49.5gr IMR4350 with Sierra 75gr hpbt. For fireforming this batch of Hornady brass I used 37gr of N160.

 

[LRSickle]

Any chance to try the loaded rounds in a different rifle to see if they split in the other rifle too?

No. I have another 6mmAI but it's at my son's house in Idaho.

 

[RockyMtnMT]

I've been shooting Win and Rem brass in this gun since 2008. I've never had a problem with either. My regular load is 49.5gr IMR4350 with Sierra 75gr hpbt. For fireforming this batch of Hornady brass I used 37gr of N160.

We were doing some load development with a wildcat and trying different powders all near each other on the burn rate chart. Tried a Vit powder at what we thought was a reduced load. Had to beat the bolt open. I still wonder if that was one of those times I was lucky.

It sounds like you have found that the brass is not good enough for what you are doing.

When you close the bolt on the unformed brass is there some resistance indicating that you do not have a head space issue?

So far I like the cow method best. It seems to be easiest on the brass. We have talked about hydroforming. But the die is expensive and we have too many wildcats.

Steve

 

[LRSickle]

We were doing some load development with a wildcat and trying different powders all near each other on the burn rate chart. Tried a Vit powder at what we thought was a reduced load. Had to beat the bolt open. I still wonder if that was one of those times I was lucky.

It sounds like you have found that the brass is not good enough for what you are doing.

When you close the bolt on the unformed brass is there some resistance indicating that you do not have a head space issue?

So far I like the cow method best. It seems to be easiest on the brass. We have talked about hydroforming. But the die is expensive and we have too many wildcats.

Steve

This is the first time I've ever used this powder for anything so I went to Vihtavori website to see if it was a suggested powder for a 6mm. I picked a load just above the minimum load.

I also suspect the brass now.

When I close the bolt I feel a slight crush-fit. When using minimum loads to fireform instead of COW, I usually seat the bullet into the lands to help push the case base back against the bolt face. This time I seated them at the lands because of the slight crush I felt when I closed the bolt.

I would rather use COW. It's easy, safe, and easy on my brass. Next time I fly into Kodiak I'll try to find some Bullseye.

 

[RockyMtnMT]

This is the first time I've ever used this powder for anything so I went to Vihtavori website to see if it was a suggested powder for a 6mm. I picked a load just above the minimum load.

I also suspect the brass now.

When I close the bolt I feel a slight crush-fit. When using minimum loads to fireform instead of COW, I usually seat the bullet into the lands to help push the case base back against the bolt face. This time I seated them at the lands because of the slight crush I felt when I closed the bolt.

I would rather use COW. It's easy, safe, and easy on my brass. Next time I fly into Kodiak I'll try to find some Bullseye.

Sounds to me like you did nothing wrong.

I think we were using green dot last Saturday for 338 lap brass. 16g with corn meal on top with a tissue.

Steve

 

[tbrice23]

This time I seated them at the lands because of the slight crush I felt when I closed the bolt.
.

You are supposed to feel resistance on the parent case when
an improved chamber is heads paced correctly .

 

[LRSickle]

morning, I had this happen with a 257AI. same case. I was using Winchester brass.

these were reloads. had been fire formed. was testing loads. had head separations

and cracked cases. threw all of the reformed cases away. started with new brass.

never did find out the cause. a person asked if loaded brass should b stored, these

these cases had been stored?? this was a new barrel installed. lightbulbgun)

No they haven't been stored very long. I bought them a couple months ago. Funny thing you brought that up. The costumer service guy asked if they had been loaded and stored for a long time. He said something about the old recipe for N150(?), after being stored too long, corroding the brass in the neck and causing some kind of case failure.

My barrel, a Bartlien heavy 1-8, is several years old.

 

[LRSickle]

You are supposed to feel resistance on the parent case when
an improved chamber is heads paced correctly .

True. I also feel some resistance with my 22-250AI and 280AI.

 

[Pdvdh]

Only Hornady brass I've improved / blown out is their .375 Ruger brass to 30/375 S.I.
No problems. Seems like decent brass too.

But you've got brass too tight/brittle to expand to your improved cartridge. I wouldn't think the casing would be expanding a terrible lot that close to the case head, so it must be exceptionally brittle in the case body.

 

[FEENIX]

We have talked about hydroforming. But the die is expensive and we have too many wildcats.

Steve

I got my 1st die ever from John Whidden and I am sold.

Ed

 

[RockyMtnMT]

I got my 1st die ever from John Whidden and I am sold.

Ed

Good to know.

There is a level of fun to sit on the back deck having a beer and firing wads of tp into the air.gun)gun)gun)

Steve