OK... I put a bunch of pics on the last reply but they all didn't post...
Here's the web address where they all are:
.300RUM Kaboom

Dang...

Wow awesome photo's.Isn't interesting how this topic has recieved so much attention.Its like seeing a reck on the highway.What's with human nature.

Has the guy pulled down any of his remaining loads to see if he has the right powder and weights?

Mike

Sure glad I wasn't around when that came apart! KABOOM is right for sure. I saw one simular where the case head split and the pressure blew the bolt out. It looked a lot like that one. I wasn't around when it blew. I have a Ruger I would like to blow up but not while shooting it! Pack it with C-4 a touch it off!

Here's my 2 cents even though I'm a novice reloader.

The Savage in question allows you to switch barrels and has an interchangeable bolt head. You need a funky wrench and a bench vise.

The fellow in question sounds like he may be a little careless. So it would not surprise me if he had not properly checked or set the headspace after screwing the barrel on.

This combined with his reloads (case length probably too long as well) could be part of the problem.

This should serve as a reminder to all us handloaders, Be SAFE. I saw a old 3 screw flat
top Ruger come apart. 2400 and Bullseye ain't
the samething.

I'll hint again:
HEADSPACE, HEADSPACE, HEADSPACE.

Coupled with hot road ammo. No barrel bulge so the bore wasn't obstructed. My guess is the first round trashed the lugs, followed by the next round that blew it apart.

If he had stopped on the first round I would bet a dollar to a doughnut that the lugs were set back and the headspace was off a mile.

Schromf, I'd wager you're exactly right.

Gentlemen, I'm mystified as to how (supposedly excess) headspace can cause this end result. I'm struggling with the idea of excess headspace and the report of difficulty chambering the round.

Please explain how the headspace causes this condition.
Thanks
Vapo

quote:

Originally posted by vapodog:
Gentlemen, I'm mystified as to how (supposedly excess) headspace can cause this end result. I'm struggling with the idea of excess headspace and the report of difficulty chambering the round.

Please explain how the headspace causes this condition.
Thanks
Vapo

Couldn't too little headspace cause this condition?

quote:

Originally posted by Matt Norman:
The shooter had a problem chambering the second shot, (he had to force the bolt closed). The rifle blew up at the shot.

Coupled with an already redline load, my vote goes to excessive case length.

How many times had this lot of brass been loaded? Has anyone checked the surviving rounds of that batch of ammo for powder weight and case length?

If the case cannot release the bullet due to case being over length, pressures can skyrocket even w/mild loads. The pressure has to go somewhere!

Regards,
hm

quote:

Couldn't too little headspace cause this condition?

Hard chambering...yes.....blow up the gun???....no.

quote:

Coupled with an already redline load, my vote goes to excessive case length.

This argument is far easier to relate to.

Vapodog,

This was a cumulative problem. First he had a condition that was ignored, and case length is absolutly a suspious area. But I still think if rifle was inspected before the round that caused demolition, it would have been determined that is was not safe to fire. Then he chambered another round and blew it up.

We probably will never know with any degree of certainty. And yes there are several possible causes, a slightly oversize bullet, causing very excessive pressure spikes is plausable also.

Bottom line, this whole post reinforces why I never use other peoples reloads, and I pull the bullets and salvage the brass, even when I get it for free. Too many clowns, paying poor attention to details, makes me unwilling to risk the consequences. Trash it and start over is a golden rule, and I am very picky on this. I had some reloads of my dads that I pulled apart, his standards and mine were miles apart. No he never experienced a blow up, but after his death I took one look at his scale, then started looking for the micrometers, which he never owned, and decided that my fathers stuff was not up to my standards and pulled all the bullets and salvaged the brass.

When I was 10 years old I didn't give it a thought and I shot lots of his reloads, now I am older and wiser ( I hope ! ) and his reloads didn't really cut the muster, way too sloppy for my taste.

I have a guess.

Though the guy denies it, a .338 cal bullet probably won't chamber in a .308 cal barrel, it can, with lots of effort, be shoved back into the case. When the primer ignited, it started the bullet toward the leade, where it jammed. The powder is now spread through through more volume and having been ignited at essentially the same time, creating a pressure spike explosion, rather than a controlled burn. Under that amount of pressure, the bullet squeezed down down in caliber, gaining a bit of velocity boost over normal. If we could find the bullet, it'd be shattered into really long pieces, after its 5,000 fps journey.

It'd be an interesting process, if we could figure out how to control it other than in tanks. Maybe a little less compression...

Jaywalker

Do you think he might have put the wrong powder in this load? Might be a good idea to open some of the remaining rounds & see whats in them.

If an overpowered load or an acceptable powder coupled with excessive length brass which led to a very tight crimp AND too much pressure to begin with set the lugs back the FIRST time,..then that would INCREASE headspace,..would it not! AND if the next round did not want to chamber, then it would have to have been a HUGE margin longer than the first case which chambered suppossedly with no resistance in the pre-setback condition. I have trouble following this conclusion, not to say it isn't correct mind you.

I am going with a powder that was wrong, coupled with a long seated or excess length neck on the second round which led to a pressure curve being too much for the weakened boltface design which then overpressured the action.

The pictures look to me like the action was forced rearward so hard, that it cracked that magazine area just at/near the rear action screw and latterly down the barrel channnel in a mcmillan tactical stock which is by no accounts weak material. I see a massive rearward push which not only made the action yield, but the stock as well. It seems as though that poor bullet just couldn't get out of the way fast enough. But that could also be conjecture just as easily.

Howdy all,
I went back to "ground zero" yesterday and I had GREAT success.. Out of the CEILING, I pulled the top/left side of the receiver. I took a bit better pictures of it too..
Personally, I pretty much agree with JustC's synopsis based upon my discussions with the Nosler people and other people like Matt... I don't think the wrong powder issue is too likely mainly because he was loading .300RUM & .338 Lapua around the same time with the same powder (Reloader 25)... Unless it was a "new" can of R25 with a significantly faster burn rate, that is about the only way I think the powder could be "different"..
Personally. I think the load was "hot" like I told him after the first round and I think the brass was "long" on the second round, which caused a very "tight crimp" when forced into the chamber, in addition to the crimp that was already used on that load. As JustC said, the bullet just didn't have enough time to get out of the way before the presssure went catastrophic. Take a look at these pics... The receiver was RIPPED lengthwise by the pressures. The barrel threads look to be just fine. On the barrel itself the threads are intact.. I'm just glad i didn't get hit with THIS piece as it is a lot "sharper"...




Here's the link to where these are posted:
.300RUM Kaboom2

Those pics must be too big to put together:

And this:

Here's a top view:
Here's the address where they all are:
.300RUM Kaboom2

Just out of curiosity wouls a chrome moly action have handled this better ??

WOW !
Looking at that mess makes me wish the benches at the range were a little farther apart !
My GUESS notice guess is in capitall letters remindes me of 2 things in my experence. One was a time I messed up setting a new scale, and did some rounds for my stw 5 grains high. fired 2 and the chroney told me somthing was wrong before I lifted the bolt witch was a-bit sticky, and then another time with the same rifle when i thought I was loading 81 grains of H-1000 but after loading 5 rounds noticed the can on the tables was Varget. Now that, might have been interesting ! Can't check things to many times. Oh back to my Guess. Wrong powder !!! tj3006

That's grossly high pressures to do that .Wrong powder + extra long case . I don't think a Cr-Mo receiver would have done any better.

We know a few things.

One, it was almost certainly not the wrong powder, because the chrony reading on the first shot was in the ball park.

Second, it was not a bore obstruction, because the first bullet showed up on target.

Third, excess headspace can create catastrophic case failure. I've done it, in a Savage. Doesn't hurt the rifle one bit. Does give one a terrific flinch for months, however.

We know the case was hard to chamber. We know there was an attempted crimp.

My CONJECTURE, therefore is that the crimp was put on with the seating die, AND that the case lengths varied substantially. The second case was longer, and therefore crimped much deeper. This resulted in a case deformation, as well as substantial bullet deformation. Somehow, that combination proved disastrous. JMO, Dutch.

A deep crimp wouldn't do it. A too long case that jammed the case mouth in the chamber would
boost pressure, and chamber hard.
My vote for what it's worth is a long case. If the case head had (headspace ect) let go the pressure would have been less. I'll bet the case head was ok. Whith a jammed bullet
it became a shoulder held pipe bomb.
Good Luck!

quote:

Originally posted by schromf:

...Bottom line, this whole post reinforces why I never use other peoples reloads, and I pull the bullets and salvage the brass, even when I get it for free. Too many clowns, paying poor attention to details, makes me unwilling to risk the consequences. Trash it and start over is a golden rule, and I am very picky on this....

This, my friends, in good advice. While I have been reloading for 12 years, I still consider myself a beginner and follow the manuals.

I dump and recycle the brass of every reload I get with a used rifle I buy (they often come with reloads, brass, dies etc) and work up myself to the "perfect" load the previous owner used as well.

quote:

The second case was longer, and therefore crimped much deeper. This resulted in a case deformation, as well as substantial bullet deformation.

Yes, and the throat of the rifle acting as a crimp ring is still in contact with the case and will not allow the case neck to expand and releast the bullet, thereby forming an effective plug in the bore. Any time the case cannot release the bullet, pressures will skyrocket.

quote:

Whith a jammed bullet
it became a shoulder held pipe bomb.

Absolutely.

Regards,
hm

Jaywalker, I suggested the same thing about 1 page back! I am not sure that many of the other explanantions explain the catastrophic failure that occurred, but a blocked barrel certainly would.
Peter.

Peter, I wasn't stealing your input, I was casting a vote.
Take Care!

There is one other possibility...the crimping process could have slightly bulged the case, making headspace incorrect and the case too short. The hard bolt closing is a result of the bulge being forced into the forward chamber where it is a bit too large. With the bolt closed, there is too much headspace and it separates.

The other possibility in Sabot's scenario is a bulged shoulder, which when forcibly chambered, jams the base of the neck tightly around the bullet. This is enough on its own, to ensure a considerable pressure excursion.

Happened to me, with a very mild .308 load, when I first started loading with a press [after a Lee Loader]. Had the seating die adjusted down a bit far, struck a long case.......

Considerable gas leakage, as the primer pocket was opened up to about 1/4", but fortunately no case separation.

Gadge, that scenario sounds pretty plausible, especially if the brass had been loaded a couple of times. On some brass, a ring will from at the base of the neck. It could well be that this local thickening was emphasized by the deformation caused by an improperly set crimping die (or improperly trimmed brass).

Essentially, the BASE of the bullet would have been "pinched", and not allowed the bullet to exit at rational pressures. FWIW, Dutch.

This appears to be beyond just a pinched bullet and the load listed. This looks like a case head failure (unless the barrel split) with many possible causes. Did the barrel split or crack? Did the lugs shear? Is this your rifle, I cannot imagine someone letting you keep such parts.

Unless the design chamber is cut incorrectly you cannot chamber this cartridge and pinch a 30 cal bullet without alot of force on the bolt handle with a long case neck. Its possible to cut a barrel chamber shallow allowing more case to hang out the rear or simply head space it too far, such that you have increased the chance of case head failure. Did you mess around with the headspace?

I suspect a headspace/ chamber issue or its something in the action design, if the barrel didn't split. You really have to tip the powder measure with the slower powders to pop a case head. Did his first round fired have had the primer pockets loose? or show a case bulge? Did the lugs crack/shear? Check the case protrusion from the barrel and compare with the bolt to determine if properly chambered.

If all checks well or doesn't contact Savage and foreward them the photos and ask them if this failure is as designed for a case head separation? Unless injured parties are seeking damages ask the maker for a new rifle. If injured parties are interested in seeking damages contact professional counsel.Why? I don't believe some of these big cases belong in some of the actions they are being placed in. Due to their diameter and powder capacity. If no one was injured the action splitting letting the barrel go could be argued an acceptable failure but not something I would hang my hat on so to speak.

Personally I feel this action did not fail in an acceptable manner ( provided the barrel didn't split ) and personnel were injured. I believe and action should handle loads and forces incurred with case head seperation and vent gas safetly up to the point of the barrel splitting. It won't be hard to convince 12 others as well. Due to liability and safety modern actions are designed to vent gas and handle pressures accordingly or its an oversight on someones part when this cartridge was chambered in this action. This may rattle a few cages but its how I feel regarding action design and metallurgy.

All good ideas guys... I may never find out the exact cause though (unfortunately)..
Thomas Jones, you hit the nail on the head about bench separation.. I don't think I will be able to sit next to anybody at the range anymore who is shooting their own loads without totally losing all concentration on what I am doing at my bench... I just can't trust what other people have done to their own loads to put myself into the position of possibly going through this again, or worse, being killed...
I am only hoping it doesn't affect my ability to affectively shoot .50BMG matches! The benches at our .50 matches are slightly more "separated" because of the muzzle brakes on our rifles BUT, the powder charges we use in that caliber are almost 3 TIMES what was being used in this .300RUM! And, there is basically NO "factory loaded" match grade ammo for .50BMG... If you want to be competitive at all, you HAVE TO "roll your own"... I'll probably be looking at the competitors to both sides of me quite a bit while trying to keep on my own target... Not good for the scores...
The good news is that my headaches are finally getting better...

DemoSam,
No, it was my friend's rifle...
No, besides the case being stuck in the chamber of the barrel minus the head, there is NO apparent damage to the bore at all, OR to even the threads on the barrel.. The projo is also MIA as it isn't in the bore and it didn't impact with the target when the gun blew up...
The only "part" I have is the part that I dug out of the ceiling over the firing line about a week after the KABOOM... It is the one that is of the receiver itself shown above.. As far as my friend "letting" me keep it, I don't see what the issue would be? I would minimally like a souvenir of the incident that almost took my head off... He has the rest of the parts/ammo in question..
Based upon the damage, it seems obvious to me that the factors that came together to cause this catastrophic failure all occured from the chambered/loaded projectile back... ALL the way back to the reloading bench where the rounds were loaded to an "overpressure" status to begin with...
You may be correct in you summation regarding how this action "should have" behaved, but I am also sure you have read the clauses that just about EVERY new firearm "owners manual" contains in regards to "shooting reloads"...? I think that they all have their A$$e$ covered when it comes to this topic....
Believe me, I am not looking forward to a life with some permanent hearing damage, which minimally I "may" be looking at, because of somebody else's ludicrous need for a "hotter than factory load"... Only time will tell I guess...

NEjack, exactly, the "dreaded donut".

The problem is not just "pinching" the bullet a little. The problem would be to create a bit of a "wasp-waist", with bulges front and aft. Then you have to size down the bullet before it can start into the bore. Like jamming a bullet, this increases the start pressure (which, in turn, increases the peak pressure).

Playing a little bit with "Quickload", it predicts 78,000 PSI with the accubond and 95 gr. of RL25. Stouter than I would be willing to pull the trigger on to begin with.

Now, if I change the start pressure to twice that of a jammed bullet, Quickload predicts 103,000 PSI: KABOOM territory.

Even when increasing the start pressure to 10,000 (jammed bullet standard start pressure) Quickload predicts a peak pressure of nearly 89,000 PSI.

In other words, a little bullet jamming, or bullet deformation could very much be "all it took" in this case. FWIW, Dutch.

PJS50,

I (and others I'm sure) would appreciate if you can convince your friend to do your best to figure out what happened (even if it involves getting some scientific guys involved), and report back. It would be valuble information for us all. FWIW, I put my bet on too long case neck.

Thank you, Doug

Why don't you contact the rifle manufacturer, tell them your were injured by this rifle suffered hearing loss and you were not the shooter but have pictures of the failure. Ask them if its a typical failure? I'm sure they will be more than willing to help. If it comes to failure analysis ask for an independant lab. Were the lugs setback in the action or cracked?