Saw this thread over at 24hourcampfire. Quite a bit of speculation going on...

https://www.24hourcampfire.com...hp/topics/15578344/1

A young man whose mother is a good friend of my wife was seriously injured last month at the range. He was firing a Model 70 Winchester in 7mm Remington Magnum. He fired one round with no problems, then jacked in the next round and when he fired, the rifle completely blew up on him. He lost an eye and has had two eye surgeries since then. He was using factory ammunition, not reloads. The family asked me to bring it to this forum and see if anybody with expertise had any theories or insight into what happened. This young man is not a firearms neophyte, having served two hitches in the Marine Corps and been a lifelong hunter. Since he fired the first round without incident, it is hard to visualize some kind of barrel obstruction, yet amazingly high pressure must have ensued

Every body who ever blew up a rifle was never using handloads.

There are numerous pictures of the wreckage of the rifle in the thread, and lots of comments about what it might have been. I can’t tell what era model 70 it is. The barrel looks like it has a coned breach, which would seemingly rule out a new haven post 64 model 70. The FN manufactured model 70 that is currently on the market has a coned breach like the old ones, at least the one I own does. But maybe the rifle is a pre-64. It appears to be a custom rifle from the gun stock and the rear sight on the barrel. I’ve never seen a sight like that on any model 70s. It’s also odd, and maybe telling to people who have more expertise than me, that the barrel is not ruptured. It all went out the action, which is thoroughly blown up.

Note the back thrust was such that it sheared the lower locking lug abutment straight through in the receiver. That coned breech just focused the blast backwards. Must have been a massive pressure spike. Huge amount of flowed and vaporized brass. Link showed it to be factory ammo. Or it could have been grandad's reloads in a factory box.

I can’t imagine the pressure levels that would be needed to push the bolt lug through the bottom bridge face of the receiver like that. Must’ve been incredible.

Most likely is a big charge of totally wrong powder. Rifle charge of handgun powder not just a mere over charge of rifle powder.

quote:

Originally posted by Live Oak:
Most likely is a big charge of totally wrong powder. Rifle charge of handgun powder not just a mere over charge of rifle powder.

I know for a fact that 23.4 grains of Accurate No 7 will do that to a receiver. Guy thought he grabbed the can of Reloder 7.

Nasty. Purportedly pre-64 Model 70 7mm RM firing Federal factory loads. Barrel not split. Odd looks like 1 bolt lug missing 1 recess torn out.

I’m curious if it would be possible to blow up a gun this severely with factory ammunition.

I'd bet it is a pre 64 action...but what's with the obviously drilled hole on the L side of the ring?

Remember back in the old days, gunsmiths made an inside action wrench that only grabbed the inside of the ring? Put a heck of a lot of strain on the thin R. wall!

I saw a M-70 that was fractured by the use of such a wrench.

So....I'd take a close look a the guy who installed....(what looks to me like an after market barrel)

Later in the discussion someone notes that Leupold replaced the scope for free!

I once was a participant in a rifle match at Fort Benning. During the 600 yard stage, there was a flurry of activity a few targets over from mine. I was scoring at the time and as soon as my shooter finished and I completed the score card, I went over to investigate. The shooter on the point was using a pre-64 Model 70 chambered in .308 Winchester. At some point in his string he fired a shot, scoped the result and reached up to reload, only to discover that the upper half of the receiver and the barrel over the chamber were missing. He had noticed nothing strange about the shot, it had hit the target and been scored, but the rifle was clearly destroyed.

Speculation at the time was that the barrel had a fault over the chamber and the receiver ring. I never found out what exactly was the cause of the accident, but the effect was undeniable.-

Sharp shouldered case, lots of powder capacity. My guess only ....underloaded case giving excess empty volume in the case creating possibly secondary ignition ? It did come apart in the action and seems barrel was blown free.

Gotta be the ammo. That was a nuclear detonation.

PO Ackley had pictures of a blown pre 64 in one of his reloading books. The receiver showed a very course grain structure in the receiver ring.
Just found the picture.... the receiver showed a large amount of impurities in the metal, resulting in the blow-up.

Could this be the reason the Mauser engineers erred on the side of caution with their choice of material and heat treat, third lug, gas venting etc etc?

quote:

Originally posted by metal:
Could this be the reason the Mauser engineers erred on the side of caution with their choice of material and heat treat, third lug, gas venting etc etc?

Wasn’t it Mauser who lost an eye to a case rupture? Or maybe his brother?

Yes, the Mausers were definitely over-built and that was based on years of experience. But in a case like that M70 it is obvious to the initiated that it was a catastrophic failure due to massive over pressure. Far beyond the design limits of the action. I have pictures of Mausers that came apart like that. It is well known that the pre-64 M70 had metallurgic and design flaws. These may have contributed to the amount of carnage. IOW's it may have created more shrapnel than another design like the Rem M700 or even the Mauser 98. You can see that someone drilled a big ole gas vent hole in the left wall of the receiver. It didn't help any. In fact I don't think you could have drilled enough holes to vent that blast. The coned breech left over from WW1 feeding concerns only focused the blast backwards. Now a Rem 700 is a different design concept that relies on containing the gas and not venting it-"Three rings of steel". The bolt nose is designed to expand and completely seal the breech. So they either spit out the pill and vent or the receiver expands and vents forward(at least by design).

quote:

Originally posted by metal:
Could this be the reason the Mauser engineers erred on the side of caution with their choice of material and heat treat, third lug, gas venting etc etc?

quote:

Originally posted by metal:
Could this be the reason the Mauser engineers erred on the side of caution with their choice of material and heat treat, third lug, gas venting etc etc?

LOL
If heat treated 4140 and a large bolt handle 3rd lug notch catastrophically failed from this gross overload, do you really think low/medium carbon steel and a dinky 3rd lug would have faired better?

quote:

Originally posted by BaxterB:

quote:

Originally posted by metal:
Could this be the reason the Mauser engineers erred on the side of caution with their choice of material and heat treat, third lug, gas venting etc etc?

Wasn’t it Mauser who lost an eye to a case rupture? Or maybe his brother?

Yes Willhelm lost an eye in 1901 firing the C98 self loader.

quote:

Originally posted by Doug W:

quote:

Originally posted by metal:
Could this be the reason the Mauser engineers erred on the side of caution with their choice of material and heat treat, third lug, gas venting etc etc?

LOL
If heat treated 4140 and a large bolt handle 3rd lug notch catastrophically failed from this gross overload, do you really think low/medium carbon steel and a dinky 3rd lug would have faired better?

Doug,

Did you have an abusive father who beat you with a Mauser? You have a serious chip on your shoulder about Mausers and I really can’t understand it. I stopped commenting in the other thread because it’s almost as if your having a past argument or at least the people you were arguing with weren’t in the thread? You replied to comments/opinions that weren’t there?

Would a Mauser 98 have saved the kids eye? I really don’t know. I can tell you looking at the pictures that Pre-64 has some very thin cross sections which from the poor pictures look to have been hard. There is more meat on 98, would it have made a difference with that catastrophic of a failure? I cannot think of any action that I would bet my eye as to holding up to that pressure.

With your earnest dislike of Low quality products I hope you will now chime in to every thread that a Pre-64 is mentioned and remind folks what cheap garbage they are. I suspect you would now rank them nearly as poorly as a Mauser.

Mausers are junk, I suppose that means Krags are too, as well as 03’s, 1917’s crack, 64’s grenade and 700’s peel apart, what are you going to shoot? Running out of options? Tikka? Oh, wait, no. A-bolts? No one seems to actually shoot those so the jury’s still out. Howa? Blazer?

metal, Paul suffered damage to his eye, Wilhelm passed in 82’

quote:

Originally posted by Bobster: I have pictures of Mausers that came apart like that.

I would enjoy seeing those. Would you be willing to email them to me or post them for us to look at?

It’ll give Doug some fuel for his fire.

Or yeah you’re right it was Paul.

quote:

Originally posted by Fal Grunt:

Doug,

Did you have an abusive father who beat you with a Mauser? You have a serious chip on your shoulder about Mausers and I really can’t understand it.

LOL
Mausers, 98 was a exceptionally well designed military rifle for it's time, conditions of low quality brass, escaping gas, etc and used the best metallurgy, heat treatment and cutting tools that was available then, 120 years ago.

But attaching mythical properties to the design and especially to the metallurgy is absurd.
It is like Ackley never blew up a bolt action, including Mausers.

Where else in the mechanical world do people believe that metallurgy from a century ago is superior to today?

You couldn't even build modern vehicles or aircraft subject to the speeds and stresses with steel/metal they had available 100 years ago.

And when there is a catastrophic plane crash you don't see people claiming/wondering that if the plane was made of wood and canvas the results wouldn't have been so disastrous.

But here we are.

quote:

Originally posted by Fal Grunt:
I suspect you would now rank them nearly as poorly as a Mauser.

Mausers are junk, I suppose that means Krags are too, as well as 03’s, 1917’s crack, 64’s grenade and 700’s peel apart, what are you going to shoot? Running out of options? Tikka? Oh, wait, no. A-bolts? No one seems to actually shoot those so the jury’s still out. Howa? Blazer?

^ I never said anything even close to that and really don't appreciate you claiming or implying I did.

What I said was,
"If heat treated 4140 and a large bolt handle 3rd lug notch catastrophically failed from this gross overload, do you really think low/medium carbon steel and a dinky 3rd lug would have faired better?"

Feel free to answer that if you care to.

Hey hey c'mon Doug this thread is for bashing the Mod.70.

No thanks, I will leave the bashing, hyperbole and emotion to those that can't discuss this topic using logic, known facts and well established engineering principles.

Doug, then quit with the name calling an condemning and stick to using logic, known facts, and well established engineering principles.

And maybe stick to the actual discussion so simple, stupid people, like me can follow along.

I replied in the other thread so as to not waste more space here.

quote:

Originally posted by Fal Grunt:
Doug, then quit with the name calling ....

You have a vivid imagination, I haven't done any name calling.

After Mauser was brought into this thread and suggested that it might have performed better I asked for the reasoning.

So far nothing.

irrational hysteria? zealot?

these are terms of endearment to you? nicknames you use for your loved ones? terms that applaud intelligence and reasoning?

If someone calls me a zealot, I don't thank them for the compliment. I don't think being a zealot has been a term of endearment since the Spanish Inquisition.

Would love to hear your opinion though on why you think it is a compliment? (I view a compliment as the opposite of name calling, just for clarification)

quote:

Originally posted by Doug W:

quote:

Originally posted by Fal Grunt:
Doug, then quit with the name calling ....

You have a vivid imagination, I haven't done any name calling.

After Mauser was brought into this thread and suggested that it might have performed better I asked for the reasoning.

So far nothing.

The Mauser still may have gone to pieces, but that full sized gas shield that blocks the left bolt raceway at the rear may have prevented the initial gas thrust from hitting the guy's eye. Early winchesters have no full block at the rear, however as years have gone by thy have increased the size of the (still small) flange there (why?). OF course later rifles have the gas block on the bolt as well.

quote:

Originally posted by BaxterB:

The Mauser still may have gone to pieces, but that full sized gas shield that blocks the left bolt raceway at the rear may have prevented the initial gas thrust from hitting the guy's eye. Early winchesters have no full block at the rear, however as years have gone by thy have increased the size of the (still small) flange there (why?). OF course later rifles have the gas block on the bolt as well.

True the 98 does have better gas handling with the bolt stop and gas shield.

"Could this be the reason the Mauser engineers erred on the side of caution with their choice of material and heat treat, third lug, gas venting etc etc?"

But I didn't question that aspect, I questioned all the rest.

Something to think about; pre 64 Model 70s were made from bar stock; fully machined out of a solid chunk. Not until 64 did Winchester start forging receivers. Just a point of interest, meaning nothing.
Or does it?
In any case, I think it was a gross overloaded round. It does not take much of a receiver to hold a normal load. Until all the gas comes out the back.

Crap, I've shot Mausers and model 70s since the '50s and survived. Just lucky I guess.

Dave

No, the guy who had that happen had a billion to one odds bad thing happen, whatever the cause was. And it wasn't the action.

This discussion both here and there (24H CF) brings to mind the wreck of the Edmond Fitzgerald, and the 2000 movie "The Perfect Storm" .

quote:

Originally posted by metal:
Or yeah you’re right it was Paul.

I think Paul Mauser had the gas flow back while experimenting with automatic (semi) rifle.

Despite his genius Paul Mauser could never deliver on an automatic action (semi).

I have my thoughts on the rifle in question. However, I am not an engineer, metallurgist, and do not have access to the ammunition or action. Personally, speculation on a public forum seems inappropriate since the user was so injured.

Someone suggested sending the ammo to an independent lab for pressure testing. This should be done.

The young man can never be well. I hope he can be okay.

Had WBY MK V in 300 Win mag years ago and was shooting Browning factory ammo ,when the action filled with smoke ,nothing else apart from that ,when I checked the case, it had a crack through the base of it near the rim ,made me appreciate my WBY more. Even factory ammo isnt infallible .
Lesson for us all ,always Double check your ammo and never assume anything !!

quote:

Originally posted by LHeym500:

quote:

Originally posted by metal:
Or yeah you’re right it was Paul.

I think Paul Mauser had the gas flow back while experimenting with automatic (semi) rifle.

Despite his genius Paul Mauser could never deliver on an automatic action (semi).

I have my thoughts on the rifle in question. However, I am not an engineer, metallurgist, and do not have access to the ammunition or action. Personally, speculation on a public forum seems inappropriate since the user was so injured.

Someone suggested sending the ammo to an independent lab for pressure testing. This should be done.

The young man can never be well. I hope he can be okay.

Yes, sadly the user was severely injured. But I don't see "speculation on a public forum" as inappropriate. Near as I can tell, the OP (and the shooters family) on 24HR CF asked for input on the situation.

Look at what is going on 24 Campfire and to a lessor extent here with the asinine comments and name calling.

Also, no one can know why the rifle went to part wo a independent lab testing the rounds of remaining ammo or the metallurgy of the action itself. We are just guessing, and that helps no one.

Below is what happens to a modern Mauser action (Howa) when subjected to extreme over-pressure from a case full of BlueDot. Note that the barrel appears undamaged. The shooter sustained only minor cuts.

https://thefiringline.com/foru...8&highlight=blue+dot


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