6.5 cm load too hot. what now?

[wagonman]

Was the plumb sauce on the tissue not a dead give away?

he was pretty easy to spot

 

[Kracken McGraw]

Can't really tell now, but a .277" bullet in a .264 bore would likely do that too. I have gotten different caliber bullets in boxes before, mostly with the big red H, but it does happen and can be close enough to miss.

Has anyone here set a .277 bullet in a sized .264 case? Seriously asking, wouldn’t it take a lot of force and be unmistakable.

 

[Ol Thumper]

I haven’t but this guy may have used a hammer and crow bar and thought that was normal.

 

[Tokay444]

I doubt very highly there’s enough neck clearance in his chamber to have been able to get a 6.5 Creedmoor case stuffed with a .277 projectile in there.

 

[milboltnut]

My Hornady manual lists Superformance which is way slower than 4451. I wouldn't say excess pressure would be from a slower powder... don't get me wrong even a slower powder can create high pressures if gone over the edge. I guess the only thing I can say is, back off on the charge. Did you have room in the case before you seated the bullet?

I just read the write up on Hodgdons site about IMR 4451... .243 up through 416 Rigby listed on the canister??

That's a bit broad to my liking.....

 

[338 dude]

Too much powder or oil in the chamber and that’s it

 

[milboltnut]

hodgdons site load data shows 41 grains max. I usually stay 2 grains from max.

 

[KMart]

Another possibility is a severely UNDERCHARGED case with slow burning powder can present itself in the same manner.
The statement below is from the internet, so take it for what it is worth

One unusual phenomenon occurs when dense, low-volume powders are used in large-capacity rifle cases. Small charges of powder, unless held tightly near the rear of the case by wadding, can apparently detonate when ignited, sometimes causing catastrophic failure of the firearm.

 

[milboltnut]

Another possibility is a severely UNDERCHARGED case with slow burning powder can present itself in the same manner.
The statement below is from the internet, so take it for what it is worth

One unusual phenomenon occurs when dense, low-volume powders are used in large-capacity rifle cases. Small charges of powder, unless held tightly near the rear of the case by wadding, can apparently detonate when ignited, sometimes causing catastrophic failure of the firearm.

checking each case by eye before bullet seating

 

[KMart]

but in this case it's not under charging.

How do we know that he did not accidently undercharge the case?

 

[ATFIV]

Could a patch left in chamber cause a pressure spike like this?

 

[Tokay444]

Could a patch left in chamber cause a pressure spike like this?

Leave a patch in your chamber and see if you can even chamber a round.

 

[itchyTF]

How about a borescope to see if there's anything unusual? Not sure what but wouldn't hurt.

 

[457ciSBC]

I haven’t but this guy may have used a hammer and crow bar and thought that was normal.

Hey what’s 80K psi amongst friends.....

 

[milboltnut]

How do we know that he did not accidently undercharge the case?

I edited my post , yes you are right, possibly could have

 

[BDman]

I heard a fellow at the LGS telling a similar story. He had switched his powder dropper from pistol to rifle (just dumped the hopper and refilled) without ensuring all the pistol powder had been emptied. He didn't know to run the dropper a few times to completely empty it. Obviously didn't notice the mix of powders either.

 

[LCazador]

thanks for answers, at least i was within the limits. Yeah ill pull them and re-weigh... i also loaded some other rounds that day for 300 blk with same scale setup and everything was A-ok.

I guess ill start them off at 36.6?
What would cause that giant primer dent ? i noticed when i was putting the primers in they were pretty hard to get in there...

its winchester brass.

Seems my COAL is the big issue, based upon previous post.

You say it's Winchester brass but the case you show in your pic above shows a Federal headstamp?

 

[BDman]

If OP mixed Win brass with FC he's gonna have issues. Win is probably the thinnest, most spacious brass. FC is the thickest I've found - even compared to Peterson or Lapua.

 

[milboltnut]

Remington is thicker than Milsurp... so Win and Fed wouldn't be the issue

 

[Ol Thumper]

How about a borescope to see if there's anything unusual? Not sure what but wouldn't hurt.

He won’t drop the powder to measure it, think he’s going to run a borescope up the tube.