Case blew up during rapid fire. Help me!

[ezra650]

1 hour ago, 36873687 said:

It’s easy use hundo case gage. Then look over head stamps. 

Yeah... I need a Hundo in 9mm. But then you have to remember all the headstamps!! Also the brass I'm buying will cull crimped primer pockets as well. Unfortunately I'm still a peasant and do not have a 1050 lol 

 

At $115 per 5k shipped I'm fine with buying it. Dump in casefeeder and reload. Of course I will recycle it as well. 

[jlow]

The 3.2 grain of TG under a 147 grain bullet is not a light load.  Most likely you have a step case with fatigue and resulted in case head separation which is not a dangerous situation.  You get a little leakage but the real problem with this is normally the bottom of the case will eject but the neck stays in the barrel which makes loading another round impossible so a show stopper for your stage.  Easy to remove – just run a brass bore cleaner into the barrel and pull it out.

[HesedTech]

4 hours ago, jlow said:

The 3.2 grain of TG under a 147 grain bullet is not a light load.  

 

It’s not?

 

3.2 of TG gives around 130 power factor, depending on gun and bullet. That’s far from a heavy, major or P+ load. I guess it comes down to what you define as a “light load.”

 

3.2 grs of TG under a coated 147 is a very soft shooting load and hardly stresses the modern pistol. 

 

I believe the issue of the OP is, what may have caused the problem? Was it a “stepped brass” or something else; unless we see all the case parts we can only guess. I think the OP’s real concern is how to prevent it from happening again. The answer is for him to examine his processes and make sure everything is done well.

Edited April 17, 2019 by HesedTech

[Sarge]

5 minutes ago, HesedTech said:

 

It’s not?

 

3.2 of TG gives around 130 power factor, depending on gun and bullet. That’s far from a heavy, major or P+ load. I guess it comes down to what you define as a “light load.”

 

3.2 grs of TG under a coated 147 is a very soft shooting load and hardly stresses the modern pistol. 

Yeah, that’s pretty light. I think I ran 3.4 TG when it tried 147’s.

[jlow]

What I meant by 3.2 grains of TG is not a light load is the load is not light enough to cause a pressure spike (i.e. Drewbeck's comments on page 1).  It is clearly not a heavy load but it is also clearly a SAFE load that many people use, and which CANNOT cause the problem he saw.  let's not argue over semantics but looking for the reason for the OP's problem.

Edited April 17, 2019 by jlow

[HesedTech]

Jlow 

 

Got it!

 

Thank you. 

 

 

[CHA-LEE]

I have lost count of how many "My stuff blew up and the front half of the case is stuck in the chamber" threads that have been created so far. They ALL end up being due to stepped brass. How do people reloading 9mm not already know about this stuff????

[Steve RA]

Probably a lot not on the web site or another shooting web site.

[AHI]

2 hours ago, CHA-LEE said:

I have lost count of how many "My stuff blew up and the front half of the case is stuck in the chamber" threads that have been created so far. They ALL end up being due to stepped brass. How do people reloading 9mm not already know about this stuff????

Only two going on right now.    And i've lost count also.

[rowdyb]

Crap brass. You just got unlucky. 

 

I've removed cases separated like this by sticking a coated bullet in the chamber and twisting it inward to bite into the casing and the pulling it backward while twisting. Pretty simple and quick.

[rowdyb]

I've also rarely had issues with mud or tumbling media staying in the case and drastically reducing the space and creating a high pressure environment. 

[theWacoKid]

On 4/15/2019 at 10:36 PM, Tawadc95 said:

Can you all explain why stepped brass is:

 

1. Made in the first place

2. What is the purpose of the step

3.Why factory loads work with stepped cases

4. Why do occasional hand loads have a problem with stepped cases

 

I have been loading 45acp for 30 years but am fairly new to 9mm and just this past year have seen my first step cases from gathering brass after a class

 

thanks

 

 

4.  While stepped cases do have reduced case volume the issue is the sharp transition in the case wall. Basically a textbook stress concentration where the case is highly stressed from a sharp change in hoop stiffness. After a few cycles of expansion, contraction, resize, expansion the corner will start a crack and come apart right at the step. This happens when reloading this brass no matter how hot it's loaded. Overcharges won't fail this way, stepped cases always do. Avoid it. 

[Tawadc95]

Waco,

 

Makes sense to me, thanks.