Does this look like over pressure to you?

[yorketransport]

What does everyone think? I pulled this out of the chamber while fire forming 6.5 Badger brass.



I'll wait to hear a couple responses before giving any info on this. Biggerhammer doesn't get to play though.

[bear]

Looks the same as some brass I took outta my 300rum I was handloading. It needed a touch less powder

[BULLBLASTER]

I’ll bite...

Excessive headspace? Primer pushed out a little and then case slammed back to the bolt face and squashed the primer.

If you hadn’t mentioned fireforming I’d say ya overpressure. But there should be some flow into the ejector.

[Magnum_Willys]

I would back off for fireforming but may be fine for second loading

[Jolten]

Not fully seated primer?

[yorketransport]

To confuse everyone a little more, the powder used was Trailboss.......

[BULLBLASTER]

To confuse everyone a little more, the powder used was Trailboss.......

I live in a constant state of confusion.

My new theory is you just suck at fireforming... do it better next time sir.






Mostly because I know nothing about nothing related to fireforming or trailboss and can’t even think of anything that would sound smart. 

[yorketransport]

To confuse everyone a little more, the powder used was Trailboss.......

I live in a constant state of confusion.

My new theory is you just suck at fireforming... do it better next time sir.

You may be on to something here! I'll admit that forming 6.5 Badger brass from the original 338 RUM parent case is a lot easier than forming it from 7 RUM brass. I just have a couple hundred 7 RUM cases left over from a different project and this seemed like a good way to waste them.

I will say that your excessive headspace comment does come into play here. Since I'm headspacing off of a false shoulder, the case does move forward slightly from the firing pin strike, which can cause the primer to back out slightly.

[Reidus]

its not cratered like a normal factory gun gets with high pressure but you maybe have a custom action with tighter tolerances so no cratering?

Regardless it take some pressure to make a primer that flat.

[Jonathan_S]

My fire form loads always have exceptionally flat primers despite low charge

[yorketransport]

its not cratered like a normal factory gun gets with high pressure but you maybe have a custom action with tighter tolerances so no cratering?

Good observation! This was shot in one of the new ARC Nucleus actions. The clearance between firing pin hole and the firing pin is very tight. Also, the ejector is a mechanical style so an ejector mark would show up as a rectangular mark on the case head.

Now, one more bit of information to confuse everyone. The case head expansion was only .0038" on a new, never fired case.

[bullfisher]

Could have been from not jamming the bullet into the rifling when fire forming. Could be from excessive case growth in the chamber. Either way, that case is getting a run at the bolt face.

[yorketransport]

Could have been from not jamming the bullet into the rifling when fire forming. Could be from excessive case growth in the chamber. Either way, that case is getting a run at the bolt face.

Getting closer!

[Fl0und3rz]

I’ll bite...

Excessive headspace? Primer pushed out a little and then case slammed back to the bolt face and squashed the primer.

If you hadn’t mentioned fireforming I’d say ya overpressure. But there should be some flow into the ejector.

Maybe not excessive, but the general process seems on target.  I would expect to see washed out or flattened headstamp more than is shown.

[RadSav]

Were you running a filler?  I've never played with Trail Boss at all.  And I have very limited experience fire forming.  But I understand it is a low velocity cowboy powder.  Which probably means it hates to be compressed.  I would also think a Large rifle primer would be more stable with pressures on this powder than a Magnum primer?

Guess my response is more a question of intrigue than an answer or solution to anything.