Primer blow-out damaged my bolt face

[bwdearman]

I accidentally loaded a batch of ammo for my .308 with Large Magnum Rifle primers. Between that and increasing my COL, I apparently developed an over-pressure issue. So much so that a primer actually blew out along the edge of the primer cup. I'll upload pictures (if I can). I'm lucky I'm still alive...

When I got home and started cleaning my rifle, I noticed a fairly decent sized pit on the face of my bolt. It was easy to conclude that it was made when the primer blew. (Did I mention that I'm very fortunate to be alive?) I intend to replace my bolt as soon as my budget allows, but my question is whether or not I can keep shooting as-is. Also, can my bolt face be turned on a lathe enough to take out this pit without creating too much head space?

So... If anyone would be so kind as to offer an opinion, I would be grateful.

 

[Broz]

Take that rifle to a good Smith. There could easily be cracks in the action where the bolt lugs lock up. That rifle needs to come apart to be inspected properly. Do it the safe way, it just is not worth it.

Also I would look very closely at why this happened. I am having a hard time with it only being a primer and seating depth. Could you have mixed up powders or something? Scale need to be checked too. Weigh a bullet and see if it is correct.

Glad to see you were not hurt.

Jeff

 

[kermodie]

lesson learned.

I had a couple primers leak around the outer edge when I tried to get one more load out of well used cases many years ago. (won't do that again).
It left the same damage to the bolt face as what you have there. I have fired around 1000 loads since then with no indication of it affecting anything. That area is located at the primer/case interface and dose not support the primer, unless the load is over presure with very flattened primers. If you change bolts, you will need to check (and possibly) adjust the head space as well as recoil lug contact.

The primer is'nt flattened so dose'nt look like an over pressure issue. Maybe loose pockets.

I'm not a smith so maybe someone with technical experiance will chime in but I don't see a problem firing it again. The previous reply made a good point about having it checked out to be sure.

hope this helps

 

[backwoods83]

As mentioned twice have it looked over closely, but you had a case head burst not a blown primer. I can tell from the dark carbon ring you've been firing quite a few rounds with loose primer pockets, stop doing that! After it is looked over it should be fine to shoot as long as there isn't a berr there as well that will screw up the case heads. As far as milling the bolt face, its not a good idea, your rifle should have .002-.005" head space, if its already at .005" that leaves you .003" before a feild gauge will fit, then it is out of spec, it will cause excessive case exspansion and become really dangerous. As Broz said a primer change and seating depth adjustment is very likely not the culprit.

 

[Clark]

I have been doing overload experiments every since I started handloading 12 years ago.

Good: Ruger #1

Ok: Mauser

Bad: Rem700

 

[J E Custom]

I accidentally loaded a batch of ammo for my .308 with Large Magnum Rifle primers. Between that and increasing my COL, I apparently developed an over-pressure issue. So much so that a primer actually blew out along the edge of the primer cup. I'll upload pictures (if I can). I'm lucky I'm still alive...

When I got home and started cleaning my rifle, I noticed a fairly decent sized pit on the face of my bolt. It was easy to conclude that it was made when the primer blew. (Did I mention that I'm very fortunate to be alive?) I intend to replace my bolt as soon as my budget allows, but my question is whether or not I can keep shooting as-is. Also, can my bolt face be turned on a lathe enough to take out this pit without creating too much head space?

So... If anyone would be so kind as to offer an opinion, I would be grateful.

The first thing I would recomend is to go to a good smith and have him check head space.

This should show if you have any bolt lug setback if you have more than .002 thousandths head space I would have the bolt dye checked and make sure that everything is ok as Broz mentioned.

If the head space is .004 or more Don't wast your time or money on it, just get a new bolt
and have it head spaced by a good smith.

Your bolt may be fine though and all you need to do is reexamine your load and make the
proper corrections.

Some Things that could cause a blown primer are= Lose primer pockets, using to a hot primer
with a load that calls for a standard primer, wrong powder for the bullet weight, Bullets seated
to close or against the lands Brass with to many loads on them,Or even a listed max load in
some chambers.

The primer in the load you pictured was not smashed, so I would expect that it was the magnum
primer used (They have thicker cups and don't flatten as much as standard primers) and/or the
primer pocket was lose.

J E CUSTOM

 

[bwdearman]

Yikes! That's some messed up brass. The Winchester brass that had the problem was only fired twice before, so I'm not sure the pocket was the issue. When I decapped it, you can see where it leaked around. Something else that may have been a contributing factor is that I had recently used a tool to debur the primer hole on the inside of the case. I suppose it's possible that I got a little carried away on that one and created a weakness. That won't happen again because that whole batch of brass is getting discarded.

 

[J E Custom]

I have been doing overload experiments every since I started handloading 12 years ago.

Good: Ruger #1

Ok: Mauser

Bad: Rem700

Come on !!!!!

This is a made up scenario . the action had /has nothing to do with this mess.

Jive us a little more credit than that.

J E CUSTOM

 

[Clark]

Come on !!!!!

This is a made up scenario . the action had /has nothing to do with this mess.

Jive us a little more credit than that.

J E CUSTOM

What are you inferring?

 

[boomtube]

"So... If anyone would be so kind as to offer an opinion, I would be grateful."

Okay. First, your bolt is fine. That pit is ugly but it's purely cosmetic. The pit was burned in the area between the primer and case head and that portion of the bolt face supports nothing during in normal use. The primer blow-outs always occur in that small circle where there is neither case nor bolt support for that radius of the thin cup. Note that the photo above shows the results of massive overloads but the cups didn't blow out because the cup metal wasn't defective at that weak point.

You simply had a primer cup failure and nothing more; it's not a common occurance but it's certainly not all that rare. In the last 45 years I've had it occur with batches of three popular brands I won't name because the brand doesn't matter, the blow outs have nothing to do with the primer maker nor excessive pressure. The problem is the maker's providers sent them a substandard roll of the brass sheeting they make cups from. There are ways the makers can monitor the sheeting thickness but they can't detect weakening inclusions trapped within the metal and that allows such blow outs to happen. The rest of the primers in that batch may be fine but I would try to get them all replaced. Show your dealer or the maker the photos you posted and they may swap primers with you. If not, use the rest of them for lower pressure cartridges such as .30-30 and .35 Remington, etc.

 

[RTK]

What are you inferring?

I believe he is saying it has nothing to do with who manufactured the rifle, but more to do with the chamber dimensions.

 

[Clark]

I believe he is saying it has nothing to do with who manufactured the rifle, but more to do with the chamber dimensions.

J E Custom used the pronoun "this" and you use the pronoun "it".

Both are ambiguous reference of pronouns.

 

[RTK]

LOL, I guess you didn't infer that one rifle manufacturer was good and another bad............ At least I didn't dangle my participle

 

[J E Custom]

OK .
I didn't want to start an argument but I guess I do owe the poster an explanation.

The first thing that the poster implied was that these were all the same loads in 3 different actions.

The brass is military Lake city and looks like the primer pockets have eather been reamed (Required)
if it was crimped or has been shot a lot and the primer pockets are not tight.

The first load looks like a normal load as far as pressure but the firing pin hole is on the lose side
and allows the primer to ex trued into the bolt. (Not to bad for normal loads)

The second load was over pressure and with a loose primer pocket moved back and pierced
the primer pushing the anvil out of the primer cup and there is some ejector marks because of over pressure.
The Inside of the primer pocket is scorched and had the primer not been pierced it would
have blown possibly cutting the bolt face.

The third round is the real problem. It was a grossly over loaded round and stuck in the
chamber so hard that the extractor cut its way out through the case head durring the
process of beating the bolt open. also the use of a cleaning rod or something to beat the
case out of the chamber is what caused the damage to the case web. It was stuck so bad
that the hammering cracked the web of the case and even enlarged the primer hole.

If head space had been excessive the last two cases would have separated just in front of the
web. This is a classic case of loose primer pockets and excessive overloads and had nothing
to do with the rifle/rifles they were fired in.

I would not use this action again, or at least until extensive testing was done on the action
and the bolt.

People bring me stuff like this to fix all the time and and don't realise how close they may
have come to destroying a life or at the least a good rifle.

I don't care what rifle these rounds were fired in this was a simple case of over loads on
military cases.

I fired military brass for 14+ years In National Highpower matches never had a problem
and read many times that you should reduce the book loads for military brass because of
primer pockets and less case capacity.

PS: I only used Lake city brass then and still do and I have fired in excess of 20,000 rounds
of it.

Reloading is a fun and rewarding part of shooting but it can also be a killer if done without
respect for what can happen.

I will say to all reading this "Don't substitute componants unless you start low and work up
using the same componants and especally if you are going to use military brass.

The problem I had was the implication that it was a particular rifles fault not the load.

Again ; sorry if I offended any one but someone had to say something.

J E CUSTOM