Flash hole errosion

[tonysnoo]

I noticed that some of the flash holes on my brass are eroding or corroding.

The brass is 6.5 Alexander arms(lapua) Grendel necked down for my 6mm fat rat. I have been using cci450 SRM primers with a decently fast load of CFE. No pressure signs or flattened primers, pockets are reasonably tight considering I have fired them at least 6+ times. I do get a little ejector mark now and again.

The erosion is pretty dramatic on some, almost like two standard holes wide. Others have a nice round hole at the bottom of a funnel shaped eroded area. The brass with slight erosion has a nice round hole with a keyway/wide crack, when viewed from the inside. My buddy thinks it was just a factory defect in the brass and that I just didn't notice before????....six firings??? maybe???.

It looks like I have lost about 18 out of 100. Another 4-5 are showing the keyed hole/wide crack appearance from the inside even though those viewed from the primer pocket look great.

Any ideas? Thoughts?

Thanks

 

[bheadboy]

brass failure possibly, but most likely the mag primer.

Bob

 

[357Mag]

Tony -

Howdy !


Did you happen to do any inside flash hole "reaming " ( uniforming ) on the cases in-question ?

If the brass has flash holes that were broached and not drilled, there may have been some " winglet " looking materiel on the inside.....
an artifact of the broaching process. These may have been visible, prior to their being removed by a uniformer.

I'm also wondering about how "soft " the brass might be ?


With regards,
357Mag

 

[gunsandgunsmithing]

Based on loading Lapua brass well over 50 times, several times, and not seeing the problem you describe...I'd say it's powder related. I've never used CFE but have used just about everything else imaginable. Some have claimed that cfe is somewhat abrasive. I don't know that I believe that or not but can say that I've used AA and Lapua Grendel brass for years and never experienced the problem you're seeing with any kind of primer.

 

[tonysnoo]

Tony -

Howdy !


Did you happen to do any inside flash hole "reaming " ( uniforming ) on the cases in-question ?

If the brass has flash holes that were broached and not drilled, there may have been some " winglet " looking materiel on the inside.....
an artifact of the broaching process. These may have been visible, prior to their being removed by a uniformer.

I'm also wondering about how "soft " the brass might be ?


With regards,
357Mag

I had a small hole uniformer still on order when I got the brass and started to prep them, so I just checked the flash hole dia with a number drill. I pushed it in from the pocket just to make sure the flash hole was not obstructed. Other than than that no flash hole prep on this batch.

I was just thinking about when I used to clean with ultrasonic, but I was always careful to rinse, neutralize and blow dry. Maybe, did some damage leaving them in solution too long. I'm going to keep a good eye on the next batch.

 

[tonysnoo]

Based on loading Lapua brass well over 50 times, several times, and not seeing the problem you describe...I'd say it's powder related. I've never used CFE but have used just about everything else imaginable. Some have claimed that cfe is somewhat abrasive. I don't know that I believe that or not but can say that I've used AA and Lapua Grendel brass for years and never experienced the problem you're seeing with any kind of primer.

I'm guessing, I must have screwed up somewhere along the process. I will be watching the rest as well as the next batch pretty carefully.

 

[artbosco]

Thoughts? Throw them away.

 

[tonysnoo]

It pains me to admit that I shot myself in the foot. After looking at every step of my reloading process, I found a bent jagged decaping pin in my decaping die. On some brass it would scribe a line or key way though the flash hole... on other brass it would almost punch an elongated portion into the flash hole. My momma said life is like a....

Threw away about 20 brass..expensive example of impatience and laziness.