Case exploded today !!!

The chamber was cut with a .223 match PTG reamer with .080 freebore and a .252 neck. The bolt has been trued and squared and was not this pitted looking prior to this event.
 
I was shooting steel targets at 540 meters. The shot did not connect with the target. My spotter said the shot went high.


Dave Tooley said:
I'll add my 2 cents worth.

I don't see an ejector pin mark on the casehead. It should be there shining like a new penny. I don't see the smear you would get on the case head when you open the bolt. Puzzling.
I see very little brass in/on the bolt face. I would expect more if it was pressure related. Also looks like a hell of a chamfer on the firing pin hole.

My guess is a case failure, probably not due to excessive pressure. probably brass related. The expansion of the rim came from the crack running back into the primer pocket area. In fact all the way to the rim. Case ruptures usually don't run length wise up and down the case. They are normally just a pucker that opens up. On a Remington it's usually right at the end on the bolt nose to the end of the barrel. That's wear the case is unsupported and the brass is the thinnest.

I don't think it was pressure related.

Question Did the bullet go into the group?

Dave
Click to expand...
 
now that we have hashed out the reasons for the case failure, would someone explain the path of the powder & brass that hit shooter65 in the face
it would seem there was some excess clearence somewhere, maybe around the counterbore in the barrel??
also what does the actual firing pin look like??
i have a rem 700 and have got a bit of gas in the face from a pierced primer always wear my glasses and have scince bushed my firing pin
 
Damaged primer pocket during remanufacture.

Maybe primer pocket swaging tool malfunction, or primer pocket crimp removal problem, whatever their process is, combined with over pressure.

It's interesting that some people say overpressure, and some do not? Personally, I back off a load when I see primer cratering, but that's just me. I've often wondered why some rifles will flatten the primer edges and case head, while some show a crater, like this one. I'm assuming headspace plays a role.

I've heard of getting brass chunks and other material under the swage and damaging the primer pockets. I wonder how the production ammo shops catch this damage?

I know some people like LC brass, but I do not like dealing with the crimps, flash holes, sealer etc. That's why I have 5 gallon buckets of it lying around, i'll probably never use.

Ben
 
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Bob Kingsbury said:
The finish on the bolt face is common to the economy grade
Remington sold today at the low end. That same finish
covers the bolt and barreled action and bolt face. It is a textured
mat finish, but very durable. It transfers at normal pressure. What
can be seen of the bolt shows this
Click to expand...

I have a .223Rem and a .308Win that have the exact marks left by the boltface. They are the newer VSF rifles. in black matte.
Ron Tilley
 
jackie schmidt said:
If you look at the ouside radius of the primer, it doesn't appear to be that flattenned.

As for the crater, that is typical Remington. Big firing pin, sloppy hole to pin fit..........jackie
Click to expand...

what jackie said...
 
i said it before and i'll say it again.....look at the dates on that brass.

who knows how many times it has been reloaded.


will not shoot it in my rifles...and i have 7 223's..opps 8 223's

mike in co
 
Same rifle, Federal GMM case and Black Hills match red box case.

caseBHmatch10001.jpg


caseGMM10001.jpg
 
note as i have said before, black hills has used current brass in thier reloaded ammo...an wwc 06...not a 90 something.

and the primer is cratered but nice corner radius.
 
I know of no commerically available reloads that the cases have been loaded more than once prior. How do they make sure of this. From where they purchase the brass. Most brass used for commerical reloading come from factory testing or the military and is once fired. They do not buy brass from individuals because of liability problems.

I might try and get a hold of a friend who was an ammo ordnance officer when the failures occurred. The more I have thought about this overnight, it seemed the brass chemistry was wrong and was to brittle. The brakes were really thrown on by the pentagon quick....word travels fast when a front part of a bolt ends up in the guy shooting next to him. At first, it was thought that the bolt failed first (the temper of these M16/M4 bolts has always been a source of debate) but it was the case.

Hovis
 
hovis,
i woud say you are sorta right.
large commercial, we would think so, but 3d with a hornady label did not. i cannot believe someone would use brass that old and calim it was once fired.
smaller commercial reloader may not be as descriminating. i sell to commercial reloaders. i only sell once fired or black hills reloaded brass. they know what the get from me.
what is in that box is similar to stuff i scrap....bright polished OLD brass.

mike in co
THE COLORADO BRASS COMPANY
 
Mike,
There is something fishy on this brass. From the lot number, it looks like it was loaded in 2003 I believe. If the brass was made in 1998 and the problem with it was found in 1999. Then the army would have held it for about a year while failure anaylisis was done and then DRMO almost a year to gather and scrap so this brass may have not made it on the market until 2000 or even later. If this is not the brass I'm thinking of, then it probably was shot until 2000-2001 which wouldn't make it all that old. One of the reasons I do think this is the brass...is most of the good 1998 ammo didn't start getting burned up until after 9/11 either in Afghan or Iraqi. The initial ammo i was issued overseas in 2003 was 1996 I believe and then it quickly jumped to 2002 (which was the last I carried).

Hovis
 
Looking at the last two pictures confirms an issue with the firing pin fit. I'll bet the Federal was loaded with standard 205's and the Black hills used those primers with thicker cups to hold up to high pressure in an AR with a sloopy firing pin hole.


Dave
 
Just a couple of observations/opinions here. That bolt face must have been bead blasted if it was trued and it seems to have a chamfer in the firing pin hole which is not factory. Perhaps made by a live center in the hole if it was chucked up or even caused by bead blasting.
Cratering is caused by many things and is common enough to be considered normal for a factory rifle. The firing pin fit and shape are the two biggest culprits. A long, small radiused firing pin tip even with a tight fit will crater. If you measure protrusion against actual strike depth on a fired case it will be about half. After the firing pin makes a .045" deep dent in the primer, the pressure pushes the dent back out. Kill a primer and strike it, wow its a deep hole. The small radius tip allows an excessive amount material to pile up around the edge causing a crater. The cup material gets thinned out because it was stretched considerably and is not as thick nor as strong as it was before the strike, a soft primer magnifys the problem. Add a poor pin fit and you got a serious looking crater problem.
Those primers are not even remotely flattened imo and the pitted look is from the bolt face condition, as mentioned.
The case protrusion certainly does look excessive from the pics, and thats taking the chamfer into account. Better get that checked out. Still, it seems to me to be a faulty case blow up.

Glad you were wearing glasses.
 
1) In a case failure like this pieces will come out of the gun. That you got gas dusted once with no bad results just means you got off easy.

2) The bolt face photos show a texture that matches the primer imprints. If it was "trued" they either didn't touch the bolt face or they put a rough finish over their work. I suspect the former.

3) The firing pin fit is bad but didn't cause this blow up.

4) Might a visual inspection of the case shown the problem in advance? Maybe but I suspect not.

Looks like a good argument for shooting glasses.
 
High Pressure?

The chamber was cut with a .223 match PTG reamer with .080 freebore and a .252 neck
Click to expand...
Would the tight neck chamber and brass with maximim wall thickness (unturned) keep the bullet crimped in the chamber making pressure go way up? What is the neck OD of the unfired rounds ? All the primers look like high pressure to me.
 
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Dave,

What do you think is the issue is with the firing pin?


Thanks,

Mark


Dave Tooley said:
Looking at the last two pictures confirms an issue with the firing pin fit. I'll bet the Federal was loaded with standard 205's and the Black hills used those primers with thicker cups to hold up to high pressure in an AR with a sloopy firing pin hole.


Dave
Click to expand...
 
243winxb said:
Would the tight neck chamber and brass with maximim wall thickness (unturned) keep the bullet crimped in the chamber making pressure go way up? What is the neck OD of the unfired rounds ? All the primers look like high pressure to me.
Click to expand...

min spec for 223 is .250.....so not likely...

look at the outside edge of the primer...it has a nice easy radius..it does not fill to the edge, and then match the bolt face way out there too.


mike in co
 
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