Got lucky!

[FroFro1]

 

[FroFro1]

25-06 Remington. Not sure what happened. Case looked fine before loading. Not even close to max charge. Guess I didn't know internal condition of case. It came out of the chamber with that dent. Case measures 2.492. Charge was 53 grains Hodgdon Superformance. Guessing the case was fatigued.

 

[FroFro1]

87 grain Speer Hot-Cor.

 

[Enosiophobia]

I've had that happen as well. Looks like gas blowby.

 

[Kracken McGraw]

Undercharge maybe.

 

[Walt Krafft]

Too low of a charge. It did not seal the case mouth and was blowing back around the case.

 

[rwj]

May be I’m missing something… but it looks like the case head has partially separated allowing gas into the chamber…

 

[searcher]

May be I’m missing something… but it looks like the case head has partially separated allowing gas into the chamber…

Yes -indeed. I too think undercharge resulted in pre-detonation.

 

[FroFro1]

Hodgdons info.

 

[BoydAllen]

Have you reloaded this case several times? The split is in the right location for a separation caused by repeatedly bumping back the case shoulder too far during FL sizing.

 

[FroFro1]

Have you reloaded this case several times? The split is in the right location for a separation caused by repeatedly bumping back the case shoulder too far during FL sizing.

I believe that this might be the case as I haven't tracked the whole history of this cartridge.

 

[FroFro1]

I usually reload until neck splits.