What could cause this?

[Elite Precision]

Pics of the previous cases would be nice, may show a bulge from a overdone feed ramp

i did not see any bulge in the previously fired cases. just the scratch line as mentioned in the above update. when you say overdone feed ramp, are you referring to the ramp on the action, or the chamfer on the chamber entry of the barrel? and what could i do to check for this and repair? thanks for your input.

matt

 

[Elite Precision]

Excessive chamber headspace is my guess. Caused case head separation.

this would be proven by using go/nogo gauges correct?

 

[243winxb]

distinct scratch mark,

Looks like you found the problem.

Yes, the gauges help. If a rifle will chamber a field gauge, it should be inspected and repaired.

The imprint in the bolt face is high pressure for sure.

the bolt face did have a huge over pressure sign of the entire case end imprinted on it with legible writing!

 

[Dusty Stevens]

Excessive bolt nose clearance is my guess. It cannot physically blow out that far forward with proper support. Use plastigage or lead solder to check those clearances

 

[Elite Precision]

Excessive bolt nose clearance is my guess. It cannot physically blow out that far forward with proper support. Use plastigage or lead solder to check those clearances

i agree. but, if it were in excess, wouldn't it blow out on the first or second shot fired? why would there be a problem on round 24?

 

[Dusty Stevens]

Wasnt the first box factory ammo? Then a few reloads then boom? Weak piece of brass with a strong overload. Either way it cant blow out there unless the chamber isnt right- proof loads dont

 

[243winxb]

This>

Excessive bolt nose clearance is my guess.

High pressure welded the brass into the bolt face of this Rem 700.
Shooting factory new Winchester 55gr ballistic silvertips, this model Rem 700 locked up the bolt. A gunsmith had to remove the barrel to get the bolt open. The brass is welded to the bolt face. http://www.thehighroad.org/showthread.php?t=579068 See post #20 photos

Edit/add- Weld-

cause to combine and form a harmonious or effective whole.

 

[Elite Precision]

Wasnt the first box factory ammo? Then a few reloads then boom? Weak piece of brass with a strong overload. Either way it cant blow out there unless the chamber isnt right- proof loads dont

the first box was factory hornady match ammo, then the next 4 were factory nosler trophy grade ammo. the 4the being the one that blew. nothing was handloaded.

 

[Bill K]

Pics of the previous cases would be nice, may show a bulge from a overdone feed ramp

But a overdone feed ramp, would still be far behind a closed bolt into the lugs and the round in the chamber, while the shooter aimed, pulled the trigger and the bullet hits the target where he was shooting.

 

[Bill K]

the first box was factory hornady match ammo, then the next 4 were factory nosler trophy grade ammo. the 4the being the one that blew. nothing was handloaded.

Probably your best action, with this info now posted, is to talk to and probably let Nosler and their experts look and check out your rifle and the remaining rounds of ammunition you have.

 

[gunsandgunsmithing]

But a overdone feed ramp, would still be far behind a closed bolt into the lugs and the round in the chamber, while the shooter aimed, pulled the trigger and the bullet hits the target where he was shooting.

I think he's referring to the chamfer at the back of the chamber.

What make and model gun is this...Remington 700?

If so, there is nominally .150 of unsupported case on those, which is more than most and about as much as I'm comfortable with having as the solid portion of most rifle brass is roughly the same. Add in a heavy chamfer at the rear of the chamber and it can cause problems, particularly so on a hot or over pressure round.

 

[Elite Precision]

I think he's referring to the chamfer at the back of the chamber.

What make and model gun is this...Remington 700?

If so, there is nominally .150 of unsupported case on those, which is more than most and about as much as I'm comfortable with having as the solid portion of most rifle brass is roughly the same. Add in a heavy chamfer at the rear of the chamber and it can cause problems, particularly so on a hot or over pressure round.

thanks for your input.... and yes its a rem 700

 

[paperpuncher]

Measure bolt nose clearance. Can you provide pics of the chamber end with and without a case inserted.

 

[wyop]

is there anything else i can check for while this is apart? any other tests? someone from another forum mentioned to just set the chamber back and re-cut it myself. Thoughts?

thanks everyone for their input! i really appreciate it. keep them coming.


Matt.

1. I'd be looking for what's causing that line on the cases where the above case failed. Is there a burr on the edge of the chamber?
2. You didn't mention what sort of action this happened in. That might be useful.

 

[dskogman]

Too much unsupported case as stated above. This one was the 10th round and was an X. Shooter almost lost an eye.

 

[Dusty Stevens]

Look at the other picture above- the case welded itself into the boltface and still didnt blow out into the magazine

 

[Elite Precision]

1. I'd be looking for what's causing that line on the cases where the above case failed. Is there a burr on the edge of the chamber?
2. You didn't mention what sort of action this happened in. That might be useful.

it was a Rem 700 . thanks for the input.

 

[Elite Precision]

Measure bolt nose clearance. Can you provide pics of the chamber end with and without a case inserted.

i will try when i get back to the shop. thanks for your input.

 

[wwbrown]

What I find surprising is "bullet went on target at correct aim." I would have thought the trajectory of the 4th round would have differed from the first 3 given the loss of gas that blew the bottom metal and other things out.

 

[shortgrass]

Buy the way the case looks in that first pic, there's way too much cartridge case hangin' out of that chamber, unsupported.