OK HC, this link is going to make your year:

http://www.opticstalk.com/foru...s.asp?TID=19930&PN=1


A Sako 85 Finnlite in 270 Winchester went kaboom. Kinda looks like an overpressure round and a case head separation but we'll see.

Being a big Sako fan I'm sure I'll take some grief for this thread but ya gotta be honest and tell it like it is! This 85 blew up! Why is to be determined............................DJ

At least the excess pressure escaped out the magazine well like its suppose to! Could have been real bad.

"I do reload and have been for many years and am VERY cautious."
Funny thing, I have never heard of a handloader who claimed he was careless! These things happen, and when they do it causes a stir, with most people pointing to the handload itself. is there ever a case for metal fatigue? Not sure it could be proved.
Peter.

Looks like a WAY hot load.

The Finnlights have had a known problem for some time, however it usually manifests itself in a banana-peeled barrel. On this one the barrel looks intact, whereas the bolt itself seems to have failed (presumably due to a massive release of gas backward through the primer pocket).

I am a long time Sako enthusiast, but there seems to be something badly amiss with the metallurgy in the stainless Finnlite.

However, I think it is all a big lie just to cover up another massive Blue Dot explosion!

Well, I'm confused!!! I the very first line of the letter he states the first shot exploded the gun. Then farther down he states he worked up the load to max carefully!! If it exploded on the first shot ...how did he work up the load????

I don't think we're getting the whole story here!!

Sako stainless seem to have some Muslim in the blood line

quote:

Originally posted by pshooter:
Well, I'm confused!!! I the very first line of the letter he states the first shot exploded the gun. Then farther down he states he worked up the load to max carefully!! If it exploded on the first shot ...how did he work up the load????

I don't think we're getting the whole story here!!

From reading the comments it looks like he meant to say the first shot of the day, not that the rifle was new and it was his first ever shot thru the rifle.

i thought the same at first.

Just guessing pending further information, but at this point it would be hard to rule out a case head separation,subsequent to stretch just ahead of the web, caused by setting the shoulder back every time the case was resized--the firing pin drives the case forward every time the case was fired, the case walls stick to the chamber when the case expands, and the case stretches just ahead of the web until the case head has backed up to the bolt face. This thins the brass just ahead of the web, and the case will eventually fail at that point. Point is, inspect and reject cases that have stretched just ahead of the web.

Allahu Ak-BOOM!!!!

quote:

Originally posted by Mike McGuire:
Sako stainless seem to have some Muslim in the blood line

Hey DJ, I hate Ka-Booms as much as any person on the Board, but I feel sure you already know that.

Since you found that site, you may want to share these links with that guy about the discussions that were had on the GunSmith Board.

One Sako Ka-Boom discussion.

Another one.

And a third one.
-----

I can't remember if the Serial # Range of the Sakos that were Ka-Booming was listed in those threads or not. But from reading the guys comments on the one you found, he may be unaware that some of them had a problem. Perhaps his was one of those and he really did nothing wrong(except buy a Sako-junk ).

For those of you who did not originally follow those threads, the thing that riled me the most was the "lack of initial response" from the Sako Management-fools. They choose not to take immediate steps to see what was actually happening and that resulted in more Ka-Booms than should have happened.

Having something bad happen to the metalurgy is one thing, but for the Sako Management to act the way they did is far beyond rational sense to me.

Ka-Booms do nothing good for the Trigger Yanker, Factory Ammo, Reloads, or the Firearm Industry.

I got the impression that he was not injured(which says the rifle did something correctly), or did I overlook something?

quote:

Originally posted by pshooter:
Well, I'm confused!!! I the very first line of the letter he states the first shot exploded the gun. Then farther down he states he worked up the load to max carefully!! If it exploded on the first shot ...how did he work up the load????

I don't think we're getting the whole story here!!

that was my thoughts too.

HC, the original Finnlite recall was for a specifice number of M-75 Finnlites. This rifle is an 85 Finnlite and was produced well after the earlier recall.

It looks like a way hot load, the OP seems to be very forthright about what happened including mentioning a bullet hitting target very high thus indicating possible high pressure etc..

It will be interesting to see how Sako/Beretta handles it. I disagree with HC in that I think Beretta handled the earlier problem relatively well. I had models in the serial range and dealt with them vs some that comment negatively without experience in the matter.................Djpaintles (on lb404's computer)

I wonder if the gun that had the blow up was in the serial number group that had the problems. The serial numbers ranged from 419140 to 461951. It was my understanding the problem with this group was off spec stainless steel in the barrels. The failures were usually with the barrels peeling back. This gentleman was loading hot and with multiple reloads case separation would be my guess.

I don't think that a case head separation with a load generating normal pressures would do what we see in the photos. I've experienced complete head separations (foolishly reusing fired brass of unknown origin and history), but the result has never been more than a small curl of smoke escaping from the vent hole in the receiver ring. The evidence is that this gun either suffered from a gross over-pressure load or the gun itself was defective.

I had a e-mail that suggested something that is quite plausible. It very well could have been a 284 bullet stuffed into a 270 case. It's all too easy to confuse the two sizes...................DJ

But would a .284 have hit the paper? The physics dont make sense to me.

From the pictures, it appears that the case head separated or the primer was punched through. My guess, defective case. Despite Hot Cores one man mission against Sako, not the same problem as the M75 finnlites.

John

quote:

Originally posted by lb404:
HC, the original Finnlite recall was for a specifice number of M-75 Finnlites. This rifle is an 85 Finnlite and was produced well after the earlier recall.

That does not speak well for the situation at all.

quote:

It looks like a way hot load, the OP seems to be very forthright about what happened including mentioning a bullet hitting target very high thus indicating possible high pressure etc..

Actually, it it hit higher than normal for that particular Bullet, that would indicate it arrived at the Target at a "Slower" Velocity. But that is to be expected when there was a Ka-Boom in progress.

quote:

It will be interesting to see how Sako/Beretta handles it.

I completely agree.

quote:

...some that comment negatively without experience in the matter ...

For positively, absolutely 100% sure, " I " will NEVER experience a Sako-junk Ka-Boom. I do not desire that experience at all.

For those of you who do, best of luck to you.

quote:

Originally posted by djpaintles:
I had a e-mail that suggested something that is quite plausible. It very well could have been a 284 bullet stuffed into a 270 case. It's all too easy to confuse the two sizes...................DJ

I'm not so sure of that. But, and this is anecdotal, Seyfried wrote a column in Rifle (or maybe it was Handloader) a few years back regarding a similar incident. The rifle was a M70 Classic in .270 wby that a 7mm rem shell found it's way into. The photos of the rifle illustrated destruction of the rifle far beyond the that Sako. Interestingly the bullet jacket was found intact in the throat of the rifle with the jacket base and bullet core blown out of the rifle or vaporized. If I remember correctly the case head was described as being welded to the bolt head and the rest of the case being vaporized evident by a thin coating of brass on the recovered rifle parts. When I get home later I'll find the article and post the issue number for reference.

There are a number of causes which can raise pressures exponentially, but a .284" bullet in a .277" barrel isn't one of them.

If we're reducing our comments to anecdotes, P.O. Ackley wrote of a 6.5 Jap that someone had run a .30-06 reamer into, and then proceeded to shoot .30-06 ammunition. The result was difficult bolt operation and "excessive recoil". The stooge managed to shoot a number of rounds (and as I recall, even kill a deer) before taking the gun to a gunsmith with his recoil complaint.

That's a fairly extreme example of "power swaging" your bullets, but a very common example is the frequent use of "S"-bore (.323") bullets in "J"-bore (.317-318" groove) in the 8x57J round. This .005" to .006" oversized bullet is similar to the .007" oversize of a 7mm bullet in a .270 barrel. You don't find 8x57J actions littering the ground from this widely accepted practice.

quote:

Originally posted by Stonecreek:
There are a number of causes which can raise pressures exponentially, but a .284" bullet in a .277" barrel isn't one of them.

I think you're off here. Having a top pressure .277 bullet load capped by a .284 bullet is CERTAINLY going to raise pressure quite a bit, easily enough to cause a case head separation............................DJ

quote:

Originally posted by djpaintles:

quote:

Originally posted by Stonecreek:
There are a number of causes which can raise pressures exponentially, but a .284" bullet in a .277" barrel isn't one of them.

I think you're off here. Having a top pressure .277 bullet load capped by a .284 bullet is CERTAINLY going to raise pressure quite a bit, easily enough to cause a case head separation............................DJ

I would think that there is something wrong with a .270 win chamber accepting cartridges loaded with .284 bullets.

I'm no real expert here but in my 40 or so years of reloading, I've never experienced something like this. I have experienced partial case head separation once or twice but never to this degree and with no damage to the rifles. I really wonder if, by chance that somehow a .284 bullet was mixed up with a .277 cal. bullet during production/packaging. Just an idea to throw out. Sure glad the guy's ok and although the rifle is destroyed, it looks like it at least did it's job. I'll cede my thoughts to those of you with a wider range of experience than I.
Bear in Fairbanks

Since the blast happened on the first shot of the day, I would even suppose some sort of barrel obstruction due to a previous cleaning.

Being a Sako fan, especially the 75 and 85 series, seeing this brings several thoughts to mind.

One, how in the WORLD could the bolt shroud 'blow off' and not injure the shooter seriously??
I can't imagine....

I am a huge Sako fan, but am actually pretty close to HC's opinion on how Sako handled the bad batch of barrels they had out there on the 75 series at one time, which caused several Kabooms...they did handle it though, and as good or better than other mfgs have handled similar situations IMO. The Finnlites that had this issue were in the 75 series only, and I have not heard of an 85 Kaboom before this one--there may have been, I haven't heard of one.

Is there really a different gas handling design for the 85 vs the 75 as the 85 is a SEMI CRF?? I can't imagine it is, and frankly can't imagine that gas gets vented there by design...I believe and have seen that the 'fail' MO of the 75 rifle is that gas is vented through the mag well, which did happen to a large degree here...

I have had several boxes of Barnes triple shocks with a wrong caliber bullet or bullets included in the box, interestingly in all cases in .277, but I load way more of that caliber than about anything else but .30 cal. In most instances the bullets have been OVER caliber size....

The owner states he was using an RCBS Chargemaster, I have one and love it BTW, point being, the 'charger' tube on a Chargemaster will hold enough powder to almost fully charge a 270 case. If on a powder change, the charger tube still had a different powder, e.g.If the loader was using a powder such as Varget for example, I can tell you that a near full case in 270 of Varget would cause a Kaboom. Coupling some undetermined powder even with a relatively high percentage of H4350 and running max loads could certainly cause destructive overpressure, and if in fact the shooter simply had a heavier bullet, i.e. a 130 coupled with these other factors, well you get the drift--call it tolerance stack, but running max loads is at tolerance max already...

I will be very interested if we learn of how Sako/Beretta handles this one...if someone here KNOWS of the gas handling design of the 75 and 85 rifles I would love to be educated on that--it9(catastrophic gas handling) isn't spoken to in the manual of any rifle ( of any brand) I have owned...would love to know the design intent.

Amazing how folks DON'T get hurt in incidents like this often. Thank God for this fellow on that front.

quote:

Originally posted by djpaintles:
I think you're off here. Having a top pressure .277 bullet load capped by a .284 bullet is CERTAINLY going to raise pressure quite a bit, easily enough to cause a case head separation............................DJ

Head separations have nothing to do with excessive pressure; they are a function of brass thinned and weakened by excessive and repeated sizing and firing. .270 brass of normal strength (in a chamber that is not grossly oversized) will blow the primer long before blowing the case wall just forward of the head. And while grossly excessive pressure may indeed cause a rupture in the body of the case at the point, it will not cause a total annular separation of the head.

If by "top pressure .277 bullet load" you mean something in the range of 55K CUP or 65K PSI, then no, I doubt the substitution of a .284" CONVENTIONAL lead core jacketed bullet of the same weight would increase pressures enough to exceed the structual integrity of the brass, much less that of the steel of a (normal) bolt action.

I will stipulate that monometal bullets behave much differently from lead core bullets. A monometal bullet would be presumably much more resistant to swaging down due to its much harder core and might indeed raise pressures to a level which resulted in a failure of the pressure vessel.

That rifle suffered a hell of a lot of damage.

It's hard for me to believe it was caused by nothing more than a case head separation.

IF he had a 7mm bullet in there and it was jammed against the rifling and seated deeper.
thats all it would take.
it could have also been done with a 277 bullet jammed into the rifling.
and a powder that don't respond well to pressure peaking early. I-7828 comes to mind.

Just a couple of points. The bullet the OP mentioned was a 110gr Barnes. A short, monometal bullet. You'd think it more likely that a short bullet like say maybe a 120gr .284 tsx would be more likely to fit into a .277 chamber than a longer one would.

The OP never got the bolt open so we don't know if it was a case head separation or the entire back of the case blown out.................DJ

Early Sako 85's suffered from barrels made from inferior steel and had a recall. The barrel's were opening up like banana peels but i never heard of a problem with the actions. If i were to guess i'd say a double charged 270 case or casehead separation. I was worried about my Sako 85 .308 for the first several shots but i have enough through it to feel safe.My serial number is after the effected rifles. Sure glad he's still got both mitts though, Lucky.

That makes # eight of Sako Finnlight Ka-Booms.

Besides crappy steel, the beginning of the flutes did not leave the barrel thick enough in an area under the top of the time/pressure curve...bummer.

I knew a man who had shot his Pre-64 M-70 for years without any problems. His pet load was
IMR 4831. One day his rifle went KA-Boom, busted up his face, and made him a very sad
man. One day, I visited him. He was so sad that he wanted me to take his reloading stuff.
So, I went into his reloading room.
What I found, shocked me. He had about a half pound of powder. The ONLY powder he had was
IMR 4895!!!! I am certain that was the problem,
as he always loaded 59.0 gr of IMR 4831.
You load 59.0 gr. of IMR 4895 with a 130 gr. bullet in a .270 Win, you will have a KA-BOOM!!!
No Shit BUBBA!!
CHECK and DOUBLE CHECK!!!!!!