Home Forums Hunting & Shooting Hunter's Campfire another Mark V catastrophe

Don't hold your breath.

I've posted the notice just as I got it.

That's all that I'm going to do.

I have no interest in debating, persuading, or explaining.

Certainly not in blind opining.

I never buy into any story without the full facts.

Who - was injured
When - date of injury
Where - the place
What - were the injuries, what was the history
Why - was the cause claimed actually verified
How - how was it verified, how did the reporter double check claims, how can I double check reporter?

This thread has none of the above!

My view on this has been the same for many years. The MK5 action has been around since the 50's and from the outset has always been assigned the task of handling pretty much the most powerful cartridges available in any given bore size.

It's just a stretch for me to take an action that's been around that long that's spent that much time shooting bigger-than-average cartridges and assume it's not acquitted itself beyond any other reasonable expectation for something made by man and subject to failure. One almost wonders if the fact it's such a big deal when one seemingly does fail (and it's funny how often user error still seems to usually be in play) if it isn't almost a complement.

I've got an MK5 .340 and am not the least bit afraid of it. I don't know how much "better" it is than other actions but I've never seen any real world/non-anecdotal evidence to suggest it's worse.

I have 2 MK V rifles,I'll check my lugs again but they seem to have good contact. I have seen photos on Weatherby.dk where a fella stuck a barrel in the mud accidently and then fired the rifle days later and the barrel opened up like a bannana and the action was checked out ok. I find it unbelievable -this story I mean.

This thread is a reprise of an almost identical post several years ago. No hard data then either.

IF there was anything in it as a statistically valid, worrisome problem, we should expect to see several very visible repurcussions. The manufacturers and the distributors and sellers of the rifles and ammo would be tied up in court with dozens of product liability suits. And the gun hating media and the ambulance chasers we put in Congress would be in full cry to boot. Recalls would be inescapable. None of this has happened.

Of course, the UN paratroops have not landed on the South Lawn yet either, or have they?

I currently own no WBYs or WBY magnum rifles. One I did own proved to be a barrel eater but WBY replaced the barrel free because they said, on examination, it did not meet their standards. The experience was a draw.

1B

Yes it is easier to make a wild ass guess than to read the engorging reports about and action. Let me address one or two of the primary misconceptions about the current and previous action called the Mark V Weatherby.

(1) All nine lugs in contact. The reason it is not common for full contact is due to distortion in the heat treating process. It has nothing to do about the skill in machining. Machining is completed before heat treatment begins.

(2) Taken from all aspects of the different iterations of the evolution of the Mark V I believe from a design and function stand point the current Howa is far and wide the best built of all the 5 different production actions.

Let me impart a fact about the 9 lugs. The nine lugs were the result of the 59 degree bolt rotation. Does it make it twice as strong as a two lug design, not quite, but that's not where the action gets it real strength in the first place. Gas handling is of the first importance. The Weatherby design is hugely strong, but the trade off is in the heavy weight and the overall size.

Thanks Ken.

Just got off the airplane and get to read your reply.

Only question I can hope for an answer to, then, would be will you be able to give us the skinny of your "research" if others give you more information of other failures that you are gathering input from?

Just hoping your efforts can be shared with us in the future.

Allen

I already have a lot more, very reliable, very scary information that I can not divulge without betraying sworn confidences. I'll tell whatever I can � later � if I can do so without betraying confidences. That's why I have more reason than anybody else for wanting more input.

The unavoidable, undeniable general indications are two � some results of industry tests that I'm not supposed to know about �

� That some Mk V actions fail unpredictably (faulty manufacturing, not detectable before-hand).

� That some W'by factory ammo is 'way hotter than SAAMI specs.

(The key word is SOME, not ALL.)

Some of my information came from an anonymous source who wanted me to recommend a test lab for forensic examination of the failed rifle that horribly maimed and almost killed the shooter. I remember the details vividly but can not document 'em.

Some of my information came from the "shop" people who were loading W'by factory ammo on contract. They didn't appreciate the fact that their highly respected company's business people had signed a contract for loading drastically overly hot ammo.

Some of my information came from a good friend, ballistics tech at one of the SAAMI companies, whose job it was at the time to pressure-test (with modern test equipment) every brand and caliber and loading of ammo then being sold at retail in the U S. More than once, he mentioned the W'by ammo as being "worrisome," and finally gave me some hair-raising figures.

Some of my information came from a retired pilot, working as a range officer, who saw an apparently safe Mk V send zilch out the muzzle but nasty "shrapnel" into the shooter's eye.

It's damned uncomfortable to know what I know and to not be able to blaze it across the sky for all to see. (Even though I know that dyed-in-the-wool W'by-lovers could see it happen and still insist to themselves "That won't ever happen to me.")

Bottom line, FWIW � I'll never fire a Mk V with factory ammo and won't stand near anyone who's about to. One in a million � one in a billion � statistics don't mean much whnn that one is just a few inches from your face.

No, I've never seen one fail. Haven't seen all that many fired, for that matter, But when several people whom I know to be both knowledgeable and reliable relate essentially identical occurrences, I tend to accept what they're telling me as fact.

I've driven the major highways all over this continent for well over half a century without ever having a car catch fire. Does that fact guarantee that I never will have one catch fire?

I agree with DR. Howell. I own a MK5 in 30-378. While I believe the action is strong I WILL NEVER FIRE FACTORY LOADED AMMO AGAIN.

When I first bought it, I got 2 boxes of Weatherby ammo loaded with 180 grain Barnes X bullets. The first shot it blew the primer. I foolishly kept shooting thinking this was just a fluke. after the first box, I was sighted in and it actually shot very accurate. I chronographed 2 rounds out of the second box, I don't remember the exact numbers, but it was over 3500 fps!

upon opening the first box I had fired, there was three primers that had fallen out by just getting bounced around. all of the primers had blow-by, black around them.

I contacted Weatherby about it, they thought it may be the chamber in the gun, so I sent it back. they reported nothing wrong with it.I cant believe that ammo was loaded that hot.

I still shoot the gun, and it has been a very accurate rifle. But my hanloaded 180's leave the muzzle at 3410, not 3500+!

Ken, if the MK5 is as flawed as you lead on to be, I would like to know. or is it mostly factory Weatherby ammo?

while I like my Weatherby's,but I am not so loyal as to endanger myself.

Just got a PM about yet another failure that sent the shooter to the ICU. No details.

Thank you vry much for the information Ken.

And thank you for researching this. I eluded to my thoughts that some Factory wby ammo was overloaded in a recent thread I statred, but I specifically thought my memory was Wby ammo was hard to replicate the velocity it gives by handloading.

Not trying to draw out more in this thread, but I didn't get much, from how I read the replies, agreeing with what I thought was the common knowledge that Norma/ Wby ammo was hard to duplicate with reloading components available to the handloader.

Thank you

Allen

There is chance a remington 700,winchester 70,ruger 77 could blow up,there is a risk in driving your car. We can never get away from that. I have owned a bunch of mark V's and never had a problem. You can find that anything has had a problem before, it's just life.Driving to your favorite hunting spot is more dangerous than hunting itself,should we stay home??

All information, from any source, is debatable and in need of self-examination on how the information presented makes what you do with it up to you.

If you see in print: "a daisy bb gun caused a fatality", does the oddness of the initial headline mean you would ignore reading the story and determining on your own how YOU use the information, or do you read the story and use the information to help yourself in the future?

Every informative atricle has it's merits, some more than others. How you use what is read is up to you , silly or not.

I will keep handloading my MkV 300 wby, and hopefully gain knowledge from the information, if and when available, about accidents others may have experienced. There are many reloaders who have barely enough mechanical skills to do this type of operation safely, but few accidents occur.

Chicken little or no, you have the ability to use information to gain knowledge, if you choose to not do so, it is up to you to make that determination. Lessening the value of written information does nothing to help others safely enjoy firearms.

Allen

Modern pressure-testing instruments have revealed that the actual maximum pressures of typical "safe maximum" handloads run about 70,000�75,000 lb/sq in.for cartrisges that SAAMI rates as max at 60,000�63,000 lb/sq in.

Similar tests have shown that certain ammo factory-loaded on contract runs that high or higher.

Shooters keep shooting, and guns keep blowing-up.

Facts.

I don't know but I think I'd rather have a MK V than a pre 64 when pressures rocket that high.

Me too, for sure. I just did a google search looking for Mark V's blowing up and came up with nothing. If this was a significant issue wouldn't it pop up like crazy?? I can find alot of info on sako's blowing up and a few other manufacturers.

I found this on the net, very interesting reading.


Testing the Mark V Action
This fifth and final prototype action had been built with the help of
a newly-hired engineer, Fred Jennie. It was even more streamlined,
and also incorporated a new simplified trigger and safety mechanism
to reduce tooling and manufacturing costs.
Was this the safest action ever produced, as Weatherby claimed? Roy
thought that, finally, it was time to subject his new action to vigorous
performance tests. Built on the prototype action, a rifle in .300
Weatherby Magnum caliber was used for the tests. Prior to any firing,
careful measurements were taken of the diameter of the bolt face
housing, head space measurements were recorded, and all other
pertinent dimensions.
The first test firing was with a cartridge that had been loaded with
82 grains of 4350 DuPont powder, using the 180-gr. bullet. This load
gave an average breech pressure of 65,000 psi. After firing, there was
no sign of pressure and extraction was easy. The same 82-gr.load was
fired in the Mauser action and a slight sticking of the cartridge case
resulted. Four more loads with the powder charge being increased in
two-grain increments were prepared, each one using 4350 powder and
the 180-gr. bullet. After firing the 84-gr.load, there was still no sign of
pressure and no sticking of the cartridge case, even though the breech
pressure had been increased to almost 75,000 psi. When firing this
84-gr load in the Mauser action, it caused a blown primer and it was
almost an impossibility to extract the cartridge case.
When the load was increased to 86 grains in the Mark V, the
cartridge case began to show signs of pressure, but it still did not stick
and extracted easily. Breech pressures were 85,000 to 95,000 psi. A
measurement of this fired cartridge case showed that it had stretched
at the belt by .0005 inches. When the 88-gr.load was fired in the Mark
V with pressures in the neighborhood of 100,000 psi, there was a slight
sticking of the cartridge case making the bolt slightly difficult to open,
but the cartridge case could still be easily extracted. In measuring the
belt again, it had now swelled .002 of an inch, from .533 to .535.
For the final test the cartridge case was filled with powder, leveling
it off at the top. This was 90 grains of powder. Mter firing, the bolt was
difficult to open, but without exerting too much pressure it could be
opened and the case extracted. There were now extreme signs of
pressure on the case, but no gas had escaped back into the magazine
and the primers showed very slight signs of leaking. The belt of the
cartridge case still measured .535 inches. Mter this firing, a difference
between the outside diameter of the head of the bolt and the inside
diameter of the barrel of .004 inches (or .002 a side) was noted. Even
with this terrific overload, there was still no swelling or damage to any
part of the bolt, receiver or barrel. The head space was checked
between each test firing and at no time was there any change noted in
the head space.
Weatherby was extremely excited after these tests, and felt certain
that the Mark V would be the safest action of all time!
Some time later, after additional working models of this prototype
had been produced, one last experiment was made. A 180-gr. .30
caliber bullet was lodged in the throat of the barrel. A standard load of
78 grains of 4350 and the 180-gr. bullet was chambered and fired, with
the following results: both bullets traveled out the barrel, pressures
were tremendously high, the primer was pierced letting gases enter
the interior of the bolt, hitting the firing pin sleeve which acted as a
piston, loosening the bolt sleeve cap somewhat. The bolt was opened
by hand. The cartridge case remained in the chamber, but no problem
was involved in tapping it out with a steel rod. The case appeared to
be in very good condition with the exception of the primer being
pierced.
In checking the dimensions of the barrel and action, it was found
that the barrel in front of the receiver ring expanded from 1.147 inches
to 1.1496 inches. The diameter of the bolt head expanded from. 7178
to. 7190. Head space increased from .2163 to .2174. All other dimen-
sions remained the same as prior to the test.
This experiment was repeated 15 additional times. The severest test
was when a 220-gr. bullet was placed in the bore, and a standard
180-gr. round fired in back of it. On this particular firing, the head
diameter of the cartridge increased to .545 inches. It was also noted
after these additional IS firings that the head space was set back a mere
.001. This was truly the ultimate in tests for the strength and safety of
this remarkable new action.
__________________
skipper

My .340 has never fired anything other than handloads. This had always been a money issue as it gives me hives to pay $50 or more for a box of the "plain" Wby ammo, nevermind the premium bullet loads. I've only got few boxes of factory stuff I'd picked up here and there when found cheap, mostly for the brass. Now I'm almost considering just pulling the bullets.

To be honest it sounds to me like jacking the MKV action might be doing it wrong. If we're really talking out of spec ammo then the action takes 2nd place. If we widen our criteria to "guns blown up by foolish handloaders" the significance of the action used drops dramatically. If somebody held a gun to your head and handed you a 70K+ psi round and told you to fire it would you really feel that much safer with a Model 70 or 700? I wouldn't.

Ken, is there anything that points to any pattern in caliber, lot # or time frame with these ammo issue?

I had to post this one. Some kook -stuffed a 338 win mag in a 300 weatherby and fired it. Can you imagine the pressures encountered pushing a .338 bullet through a .308 rifled barrel?
Apparently the bullet came out the other end and there was slight damage to the bolt. No blow up in anyones face.
[IMG]http://i493.photobucket.com/albums/rr296/378Canuck/p1.jpg
[/IMG]

That last picture demonstrates a lot about there being shiny ejecter marks on case heads due to high pressure.

That one actually flowed back into the ejecter hole, so there is actually something to shiny marks from the ejecter being indicative of too high pressures.

Of course, the catch is we really don't know at what point the pressure becomes high enough to make an ejecter mark on the case.