Weird Deformed brass

[Dmagna]

What would cause this? Everything is normal pulled it out of the chamber like this,

 

[BallisticsGuy]

Soot down the neck and what looks like soot around the base. My guess, load didn't build pressure fast enough and gasses got out around the brass. As the case expanded under growing pressure to seal to the walls there became a pocket of gas remaining that could only be compressed so far and the last place it found refuge was right there. If my hypothesis is right then you might want a faster powder or a hotter primer or a heavier bullet.

 

[Dmagna]

Soot down the neck and what looks like soot around the base. My guess, load didn't build pressure fast enough and gasses got out around the brass. As the case expanded under growing pressure to seal to the walls there became a pocket of gas remaining that could only be compressed so far and the last place it found refuge was right there. If my hypothesis is right then you might want a faster powder or a hotter primer or a heavier bullet.

It's N570 in a 28 nosler shooting 195s. First time it's ever done this.

 

[WeiserBucks]

Possibly a poor primer that didn't properly ignite the powder.

 

[338 dude]

Too low of a powder charge come up slowly it will stop

 

[243winxb]

May need - Mag primer, faster burn rate powder, more neck tension, bullet seated deeper/shorter COL, more powder.

Gas gets past the neck/shoulder on firing. Its in an old Speer manual.

https://thefiringline.com/forums/showthread.php?t=476535

 

[jimbires]

that's usually a light load . are you scale weighing every powder charge ?

 

[Dmagna]

that's usually a light load . are you scale weighing every powder charge ?

Yeah. I have never seen it happen before. The bullet still hit within a .5 inch group with the others.

 

[Laguna Freak]

You might try a modest roll crimp, say 11 degrees rotation first. If that doesn't fix it continue roll plus mag primer. Just a thought about pressure optimization...

 

[MagnumManiac]

Have had this happen twice with 2 different cartridges.
First was a 25 Pronghorn (25-300WSM) and the second was a 7RUM.
Both times was while working up loads with ZERO data, we were extrapolating from similar sized cases and using slow powders.
Each time was a few grains below what would be a middle load, not a start load.
It is definitely from under ignition, powder starts to burn but lacks enough pressure to give a progressive burn. If we used a faster powder, we would lock the bolt up. It was a difficult set of circumstances.
Increasing the powder charge or using a hotter primer helped us.

Cheers.

 

[David Emerson]

As others have said. Not enough pressure to seal the neck. More powder

 

[243winxb]

If the bullet moves to soon from the primer firing , there can be a secondary pressure spike. https://www.shootingtimes.com/editorial/ammunition_st_mamotaip_200909/100079

Standard primers caused no ignition issues at the max load but posted higher extreme variations in pressure and velocity in the lower pressure regimes of the start loads. In extreme cases, the start loads produced short delayed firings — probably in the range of 20 to 40 milliseconds but detectible to an experienced ballistician. Switching that propellant to a Magnum primer smoothed out the performance across the useful range of charge weights and completely eliminated the delays.

 

[surgeon260]

How much N570? I use that exact combo of bullet and powder with great success in the 28.

 

[338 dude]

If the bullet moves to soon from the primer firing , there can be a secondary pressure spike. https://www.shootingtimes.com/editorial/ammunition_st_mamotaip_200909/100079

Is he using a magnum primer?