SAKO rifle kaboom

[Slater]

http://www3.telus.net/drswebspace/SAKO%20BLOW%20UP/

This one was originally over on the FAL forums. Evidently nobody was injured.

[SLCDave]

holy crapola!

[Peter M. Eick]

Thats going to cause a nasty "flinch"....

[Murphster]

I'm starting to develop a flinch just looking at the pictures. Can you direct me to the thread that tells about it?

[steveno]

are we to be lead to believe that do to the prominent display of the Federal ammo box that this was a factory load? or is this by a moron that tried to get an extra 100 fps out of his superduper reloads because after all we all know that reloading manuals are just a guide because they are always on the low side?

I guess in either instance I find it hard to believe nobody got hurt. I would that there should be at least one going to church from now on as he is one very lucky individual

[Wildalaska]

Someone didnt follow the abcs of reloading!

WildandiveseenworseAlaska

[Jim Keenan]

That incident was posted elsewhere and my analysis (FWIW) was that extreme pressure was not involved. The normal signs of high pressure (melted case head, blown receiver with intact barrel, brass melted into the bolt face) are not present. The case, though split, is virtually intact.

IMO, a barrel flaw caused the barrel to split, effectively "prying" the receiver ring apart and wrecking the rest of the receiver. The receiver appears to be cast, and there is a clear difference between the receiver breaks and the torn appearance of the forged barrel.

One poster indicated that the barrel was fluted, and it seems possible that one (or more) of those flutes went too deep and seriously weakened the barrel. It is also possible that an off-center bore (more common than you might think) contributed, or that there was a flaw in the barrel metal.

Anyway, a real train wreck.

Jim

[BillL223]

My initial take is that the bore was obstructed. I don't think you could get enough powder in the case to cause a problem of this magnitude otherwise.

[rbernie]

My initial take is that the bore was obstructed.

But the pics show NO bulges or any other signs of a bore obstruction.... I'm with Jim - I suspect a basic metallurgic/manufacturing flaw in the barrel.

[JohnKSa]

I'm in the "something was wrong with the rifle" camp. I can't imagine the brass looking that perfectly split if there had been excessive pressure.

You'd have liquid brass flowing all over the place and welded to the chamber walls.

The brass just looks like someone cut it neatly into 3 petals and folded them out carefully so as to not detach them from the cartridge head...



http://www3.telus.net/drswebspace/SA...P/SANY0022.jpg

[tex_n_cal]

Sports fans, I think this is an honest to god detonation of a less than full case of slow burning powder.

High pressure has been noted in the lab with belted magnum cases(like this one), when they are loaded with a too-light charge of slow burning powder.

Look at the "river lines" of the split barrel - the burst occured just ahead of the chamber. The bullet had started moving when things let go. All the fracture surfaces appear to suffer ductile fractures, which implies the metal is not brittle.

Remember that all moderns firearms are proof tested before they leave a factory. If the metal was truly grossly defective, I doubt it would have passed proof test. I think this is an ammunition problem.

[Gewehr98]

Remember that all moderns firearms are proof tested before they leave a factory. If the metal was truly grossly defective, I doubt it would have passed proof test. I think this is an ammunition problem.

There's a certain well-known M1A that kaboom'ed not too long ago. The ammo was not a factor. Final analysis pointed to an inferior carbon dispersion in the barrel steel - making it brittle, like cast iron. The barrel let go only after 3-5k rounds had been fired. With proper credit given to The Gun Zone:

M1A kaboom analysis

Note how similar the pictures are of the split barrels and cartridge brass. I'm thinking along Jim Keenan's lines, namely, too deep a barrel fluting job, in conjunction with an off-center bore. Add a few stress cracks between bore and barrel flute...

[tex_n_cal]

Interesting article

He is right on the money noting large grain size as a potential source of fractures...on this Sako, though, the pictures look like the fracture surfaces exhibit fine grains, and I don't see anything that looks like a pre-existing crack.

It's obviously hard to examine without the metal in hand, but I am still suspecting a wierd ammo pressure problem.

[Spy Who Came in from the Cold]

Why the case looks like it was cut with a jigsaw?
Why they don’t show us the primer of that splintered case? The overpressure marks should be clear and visible.
Why the bolt looks intact? (No picture of the bolt head)
By the laws of physics the bolt should have flown through shooters head.
Why the mag is intact?
How all splintered parts are so straight and symmetrical, not twisted? Where’s the billion-dollar lawsuit against Beretta?

[steveno]

I'm sure the lawsuit with Beretta and Federal will happen. they will give him a new rifle and scope. Federal will give him a case of ammo and everybody will be happy

[Harry Tuttle]

http://www.thehighroad.org/showthrea...hreadid=103191

This is not BPCR, but is definitely worth a look, folks. I have posted ten relatively high quality images of a brand new SAKO bolt action rifle in .300 Winchester Magnum caliber, with synthetic stock, and fluted barrel. On the 15th shot out of the box, it went KA-BOOM! The first 14 shots were from a box of Hornady factory ammunition. The fifteenth shot was from a new box of Federal factory ammunition.


The barrel is now in three totally separate, longitudinal pieces, the receiver is split down the middle, with left and right halves, and the forestock is a black plastic memory. The cartridge case is split from mouth to case head, and looks like a three-petaled flower.


With the limited number of images available - here are my thoughts on the event:


To my non-professional (since I don't get paid for my opinions,) eye this is a failure caused by included flaw(s) in the barrel steel. Once the barrel started to fail, the fractures continued forward, generally along the edge where the flutes join the major diameter of the barrel. Note, in the image of the cartridge case, there does not appear to be any significant swelling, or deformation, of the case head, itself, and I can not see any melted brass, or brass flow. I cannot see any brass flow in the shattered area of the split barrel, either. To my mind, that precludes the possibility that it was a high pressure round causing the failure. (Unfortunately, I do not yet have any images of the case head, itself, or of the bolt face, which might add additional credence to my point.)


The shooter was NOT seriously harmed because he was shooting from the bench, apparently wore proper protective gear, and had his arms cradled under the butt - in the rear sand bag area.


OK. enough teasing. Here's the link to the photos. - Rick A. Shay, Colorado

[Lone Star]

I've never seen a Sako with a "fluted" barrel. Guess the dealers just haven't had any when I was in. Haven't seen any in articles yet, either.

I HAVE seen Steyr barrels finished in a "swirl"" pattern. Is that what we're talking about? Never heard of one giving way, though.

The three even pieces of the split barrel suggest to me that this is a problem of the barrel separating along stress/join lines. I've never seen a "blow-up" photo of a rifle that had the barrel separate so far back from the muzzle, and in even pieces. But I'm no expert on this stuff...

This will be one case to follow, if it stays in the news! Thanks for posting.

Lone Star

[Gewehr98]

From the photos provided in the link, it's most definitely a fluted barrel, not a "swirl pattern" Steyr (ie. hammer-forging marks)

[tex_n_cal]

darn I wish some body had taken one more photo, like that one above, just with the pieces flipped over so you can see the fracture surfaces. I think that is where the failure started, and it would be interesting to see if there is a visible defect in the metal.

I was looking at a Remington VSSF .223 today, which looked pretty nice until I looked down the outside of the barrel, and noticed the flutes were visibly crooked. I doubt if that one shot well when it got hot.

[Gewehr98]

[Jim Keenan]

Hi, Tex_N_Cal and guys,

That business about "detonation" is a favorite theory every time a rifle blows, but detonation would destroy the case and wreck the receiver ring, not the barrel. I have seen a Winchester 70 blown with a triplex load (something that was a favorite topic in the gunzines at the time) using a hefty charge of Unique(!) and a couple of other powders. The case melted, the receiver ring let go, there was molten brass all over the front of the bolt, but the barrel landed on the ground intact. In fact, the barrel was reamed to remove the remains of the case, and installed on another rifle, where, AFAIK, it is to this day. (The shooter was seriously injured, but recovered.)

The case split is normal in this situation. The barrel splits, and the strips act like levers to pry apart the receiver ring. The case is still under pressure and it splits also, as the chamber wall support is removed. The case head here appears to be intact, with no signs of bursting or melting, so I would rule out any "detonation" or excess pressure as a cause of the blowup.

Jim

[tex_n_cal]

well, you may be right - however the .300 win mag has been specifically noted in a couple of studies to give unusually high pressures with reduced charges of slow burning powder.

I once had a couple boxes of factory .25-06 that chrono'd 300 fps below spec. I didn't pull the charges, but I suspect it was undercharged. An undercharged .300 might have been at fault here.

Gewehr I saw that one, but it doesn't quite have enough detail just ahead of the chamber.

[tex_n_cal]

Here's a cropped view of that photo - based on the "river lines" I've highlighted, the burst started just ahead of the chamber:


It would be really interesting also to pull down the rest of the rounds in that box, and see if they had normal powder charges.

[mete]

My metallurgists eyes tend to agree with tex-n-cal.Wish I could see it up close !

[Derby FALs]

Subject
---------------------------------------------------------------
Recall?


Discussion Thread
---------------------------------------------------------------
Response (Beretta Customer Support Team / JM) - 10/29/2004 02:01 PM
David,

There is a recall on a very small number of the stainless steel Tikka and Sako rifles. To find out if your serial number is affected, you may contact 1-800-503-8869 and provide them with your serial number and they would be able to let you know if your serial number is affected.

Best Regards,

Beretta Customer Support

Auto-Response - 10/25/2004 11:18 PM