Head case separation

[T-Roy]

Got a question for y'all. I'll try and make a long story short.

Got screwed on some 9mm, overcharged reloads. Had ruptures immediately. Pulled the bullets, trashed the powder, and reloaded a few with a light charge.

Shot a few of those this weekend and had another blow out. What would cause that? My guess is the brass has been overloaded and stressed before. I didn't resize it and read online improper sizing can cause separation. Anyone have any insight?

I know the answer is trash that brass... Just looking to understand more.

The casing with the larger blowout and primer setback is his. Normal primer and smaller hole is mine.

Mine where very low recoil, not close to hot loads.

Gun was m&p 2.0.

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[T-Roy]

Mine

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[Tracer847]

That primer in the first pic is cratered to hell. Did the cases have a bulge at the base when you reloaded them lightly?

 

[T-Roy]

That primer in the first pic is cratered to hell. Did the cases have a bulge at the base when you reloaded them lightly?

Yeah it is. It's hard to tell in the pic but it's also blown back beyond the cartridge rim.

If I understand the question then no. The deformed pic is opposite the rupture on his reload. The other one is mine.

On the third pic you can see where it was bulging along the rupture until the brass tore. From there on around its still straight.

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[rockyfatcat]

You said you "and reloaded a few with a light charge". How light? What is a 'flashover'?

 

[T-Roy]

You said you "and reloaded a few with a light charge". How light? What is a 'flashover'?

I'm not familiar with flash over.

I loaded 3.7 gr of solo 1000 behind a 115 gr jhp. If I can read (questionable) recommended load is 3.4 gr to a max of 4.1gr. So i guess not light, mid? But compared to factory 115 ball the recoil was extremely light.

Also, confession. Its probably been 20+ years since I reloaded. So I'm a tad rusty lol. Back then I loaded and shot several hundred rounds a week, drunk and careless, and never pulled a move like this one.



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[rockyfatcat]

I'm not familiar with flash over.

I loaded 3.7 gr of solo 1000 behind a 115 gr jhp. If I can read (questionable) recommended load is 3.4 gr to a max of 4.1gr. So i guess not light, mid? But compared to factory 115 ball the recoil was extremely light.

Also, confession. Its probably been 20+ years since I reloaded. So I'm a tad rusty lol. Back then I loaded and shot several hundred rounds a week, drunk and careless, and never pulled a move like this one.



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You have obvious bulging after the ejection cycle has started.

Flashover can happen when the powder load burns across the top of a light load as opposed to an end to end burn pushing the projectile out the tube. A primer alone can drive a bullet into a barrel. What happens if that primer strike starts the cycle and the flash happens a tad later than it should?

When I reloaded I would carefully measure the space involved and I tended to use bulkier powders just for that reason.

 

[Greybeard]

Just a thought, I think you are firing out of battery. Reloaded a lot of hot and mild shells and never seen this with a light load.
Your primer shows over pressure big time. If you loaded lite, out of battery would look like those.
I would resize, measure case length, reinspect and load another at your lite load. Do a plunk test to make sure you are all the way in the chamber.
Then set up a jig to test fire. I think when you did not resize that caused the problem? Just a dumb thought that’s not a 9x23 case?
I think I would also inspect your pistol.

 

[gyppo]

The top round was an over pressure load with powder that is too slow for that round. The pressure was still very high after the slide traveled to the rear. That is one explanation for the primer backed out. The bottom round was not a severe overload. The primer looks ok but the hole in the case indicates a problem

 

[Control for Smilers]

brass could have been originally loaded for 9mm major...then reloaded for 9mm major. prolly cooked brass.