Model 96 Swedish Mauser Accident

[sundog]

This is not the first M96 failure that I have seen. One I saw in person right after it happened was also a catastrophic failure apparently due to over annealed cases and possibly an over charge. Another was a barrel separation just back from the muzzle, cause unknown, but looked like severely crystallized metal at the separation.

I the case being discussed in this thread, is it possible that the bullet launched by primer, stopped in the leade, and then the entire powder charge ignited all at once? An obstructed bore with a pressure spike might account for such a failure.

[salpal48]

It seems the word "Drop Powder". has been Kicked around. Maybe The word "Hand Weigh". Should have been Used. It is easy to speculate after the fact. but the word Incompetent Handloading come to mind

[EDG]

That has all the ear marks of a double charge.
If you search images around the net you will find several more Swedes that look like that. They were usually destroyed by bad ammo manufactured by PMC.

[Multigunner]

A very early Carl Gustave manufactured M96 belonging to a friend had a crack in the rear of the bolt body at the apex of the pin retractor cam surface. Apparently not all these rifles were as well heat treated as we've come to expect.

To avoid double charging I place freshly resized and capped cases in a block with case mouth down, then as I charge a case I immediately either place a bullet in the case mouth ready to be seated or go ahead and seat it right then. I also usually visually inspect the interior of pistol sized cases before charging. I've found box elder bugs and discarded primers hiding in cases now and then, it pays to check.

A report on a fatal blow up of an Enfield rifle that resulted in the first ever voluntary recall of sporting rifle ammunition in the USA indicated what was likely a SEE situation brought on by a badly eroded leade. The bullet had encountered no resistance until it got about 8-10 inches up the bore then whatever happened blew the base of the bullet out and blew the core out leaving the empty jacket stuck in the bore. The pressure wave burst the case shattering the bolthead at the extractor cut out and a tiny bit of metal ended up in the shooter's chest cutting a major artery.
Similar effects have been written of involving the launching of rod type rifle grenades.

[Mr Peabody]

I wonder if there was still a boolit in the barrel when another was shot off.

[Adam Helmer]

Last year an old club member destroyed a M1903-A3 rifle and a cast boolit load on our outdoor range, with no serious injury. He is an old time reloader who refuses to remove distractions as he reloads. He has his TV on, he has his smart phone on the bench and he argues with his wife daily on the subject of the day!

I told him at a prior visit to turn off the TV, turn off the phone and close the door to wifely discourses. He did none of the above. After the ruin of the 03-A3, our club president took custody of the remaining 12 rounds of the 20-round lot of reloads into the club house for analysis. Myself and three other board members used a bullet puller and found 2 double-charged cases, via powder scale, out of 12 rounds!

Reloading requires our full attention.

Adam

[CHeatermk3]

I bought a bag of 1,000 IMI 30-06 cases, brand new. Separated them into 10 lots by weight, each "lot" +or- 0.5 gns.

Checked about 50 of the first lot of them for wall uniformity--no point in turning the necks they were better than I can make them using my Sinclair hand ONT tool. During the sizing/trimming/chamfering operation of my first lot, I felt something odd about one of the cases. There is something rattling back and forth inside the case when shaken fore-and-aft. It is a ring of brass that looks like the neck of a smaller case; I have it set on my shelf next to my beam scale.

Now, this was discovered by me the third time I handled the case in question--weigh, sort, F/L size--I noticed it as I removed it from the shellholder after sizing.

I wonder what might have happened had I just rounded the case mouth in my M-die or used the expander ball in a FL die, and loaded it to fireform, without finding the extra neck floating around inside it?

[waksupi]

There is NO SUCH THING as an SEE. It's myth, BS, oldwives tale etc.. NO reputable lab has EVER been able to duplicate it under controlled conditions. The usual culprit was claimed to be reduced loads of 4831 NOT fast burners like 2400. I have been using reduced loads of 4350, 4831 and 50BMG for 5 decades...... have yet to have any problem. When HP White can produce it I'll listen. In the meantime it's another myth that some guys sometime, somewhere said and people have been parroting it ever since with ZERO critical thinking. See: "all Republicans are white power racists" ...... samo, samo !!!

Actually,a lab in Sweden was able to duplicate the condition.

[tomme boy]

waksupi, don't waste your breath. They are the experts that have all the answers. I know it has been beat to death on here and other forums, but the common thing is the 6.5 with the long throat. As was mentioned above by someone else, The bullet gets pushed out before the charge is fully ignited and the bullet stops then the extra space that was created explode instead of burns.

Too bad Larry Gibson is not around anymore. He could show you the SEE on a trace he did. You can watch the bullet go out and hit the throat and watch the PSI spike. But we don't know what we are talking about???????

[milprileb]

The shooter is responsible for this incident. More troubling beyond the fact it happened is he is clueless of what he did...sets conditions for repeat with other attempts to reload.

The action held......and another clue...shooter says the 4th shot (the Kaboom) felt no different than the first 3 shots....shooter wants to save face and not admit responsibility. You don't have a weapon explode on you and then say" Gee, felt like every other shot fired today".

No...shooter error here and I hope he does not do it again. I am glad damage was not worse to him than what is reported and hope some lesson learned on his part will prevent it in future.

Long throat caused the Kaboom ? Yeah... how about Geese over Hudson Bay? Pick one and run with it.

[Mr Humble]

As I said (again):
1. Use an appropriate powder for the rifle.
2. When HP White replicates light loads of any powder normally safe in a gun, blowing that same gun up, then I'll listen.

As for the shotgun example: it a'int a rifle, the 6.5 didn't have a blocked bore, the distance that "pressure wave" traveled is so much farther than the length of a 6.5x55 case, it's not even in the same universe.

BTW, who goes around blowing up shotgun barrels for grins ?

A good lab given a 96 6.5x55 could determine easily how much 2400 it would take to blow up the gun.

It is painfully obvious to anyone who has loaded 10 of 1000s of cartridges and has yet to blow up any gun, that the case was overcharged.

Now lets hear about how best quality Damascus shotguns are weaker than their steel counterparts. If you don't subscribe to Double Gun Journal, you will never know the truth.

TaTa, I have to go reload some reduced 4831 cast bullet loads for my new 308 Tikka.

[tomme boy]

Here do some reading

http://castboolits.gunloads.com/show...rophic-Failure

[tomme boy]

Straight from Handloader Magazine


Handloader- readers have doubtless heard of a term called secondary explosion effect (S.E.E.). It is a theory that attempts to explain the catastrophic failure of some rifles while firing seemingly reasonable handloads or reduced loads using slow-burning powders. Theories have been offered and debated in these pages and elsewhere, but they have been just that, theories, because no one has been able to reproduce effects under laboratory conditions. The purpose here is not to debate S.E.E. but rather to report on a specific incident and the results of tests done to discover the cause of catastrophic failure.

One of the great problems with attempting to theorize on the cause of catastrophic failures is that we must do so after the fact. We have the corpse, usually with some parts missing and must try to figure out what went wrong. Learned theories are offered, sometimes conflicting, and we end up with a bunch of folks shouting in print, 'You're wrong.' "No, you’re wrong." Since the event they're arguing about what without benefit of instrumentation, either one could be right. The events I describe here represent the first instance of an event produced under controlled laboratory conditions and documented on industry standard pressure measuring equipment that provides a plausible explanation offered to explain S.E.E.

The following is simple. It goes all the way back to Shooting 101 where we learned that bore obstructions blow up guns. There are no explosions, no mysterious wave amplifications; it's just a case of several factors, combining in worst case conditions to create a bore obstruction with the bullet.

In early 1989 a major manufacturer began development of a load for the 6.5x55mm Swedish that was to be added to their product line. Development was uneventful and all work was done using the copper crusher pressure measuring system, for there were no standards established for piezo-electric pressure measurement in the 6.5x55mm. The copper crusher method of pressure measurement has been with us for generations, but it is not without its limitations. The results obtained are not true "maximum" pressures, and it provides only a single data point. There is no way that one can deduce what is happening during the period the powder is burning, nor can one see other significant ballistic events.

A quantity of ammunition was loaded using a relatively slow-burning, non-canister propellant with a 140-grain bullet. After load development in ammunition manufacturer’s pressure guns, it is common practice to function test ammunition in a variety of available rifles to ensure satisfactory performance before it is released for sale to the public.

As function testing of the 6.5x55mm ammunition was begun using Swedish Mauser rifles, they noticed some of the same signs of excess pressure every handloader is taught to look for - flattened primers, enlarged primer pockets and heavy bolt lift. All the ammunition fired in the pressure gun had been perfectly acceptable, but SAAMI test barrels and chambers are made to tightly controlled specifications so the first supposition was that some element within the test gun was contributing to high pressures. Then a "spontaneous disassembly" occurred that destroyed the action but left the barrel undamaged. The bore was clear and showed no bulges. It was immediately identified as a high pressures failure and an investigation was begun. The barrel from the wrecked Mauser action was fitted with a collar that allowed it to be mounted in a universal receiver, and an industry standard conformal piezoelectric transducer was installed. Another test was performed using the Oehler Model 82 piezoelectric pressure measuring system equipped with a trace hold oscilloscope.

(Fig !)
round pressure (psi) velocity (fps)
1 48,820 2,601
2 53,849 2,662
3 57,609 2,708
4 57,999 2,720
5 54,093 2,687
6 58,634 2,731
7 62,150 2,754
8 82,120 2,875

Pressure tests are commonly done with a 10-round string and as you can see from the chart, pressures increased very gradually on rounds I through 4. At the fifth shot, pressure dropped and then continued to increase until, at the eighth shot, pressure, went to 82,120 psi; and the technician wisely stopped the test. The raw data was then used to prepare additional graphs (fig. 1) which show that, after ignition, pressures dropped momentarily to near zero on the graph before beginning to rise again.

To interpret this data we have to first understand the ground rules applicable to pressure testing with conformal transducers. The key term here is 'offset" which relates, primarily, to the specific cartridge and the brass used therein and must be determined for each transducer and lot of brass. The offset is the amount of pressure required to obturate the case to the chamber and begin to exert pressure upon the transducer. In this case the offset was 3,800 psi so when we look at the time/pressure curves produced in the test; we must understand that we are not actually seeing pressures below the level of the offset. There is a distinct dip in the curve, however, shortly after the pressure begins to rise when it drops to a level somewhere at or below the offset pressure. All we can say for sure is that, at this point, the pressure is <3,800 psi. Engineers calculated that for the specific bullet being used it would take pressure of at least 5,000 psi just to keep the bullet moving.

As I said, there are a number of variables at work here, but the main culprit is a very long leade or throat erosion. It takes relatively little pressure to eject the bullet from the cartridge case (de-bullet), which produces a significant increase in volume. Unless the rate of gas production is fast enough to keep up with the increase in volume, pressure must drop. The simple equation is PIVI=P2V' where P = pressure and V = volume. It is helpful in considering the phenomena reported here to view the rifle barrel and chamber as a cylinder whose volume is determined by the position of the bullet at any given point in time. If the bullet is moving, the volume is continuously increasing until the bullet exits the barrel.

If P2 is at or below the pressure required to keep the bullet moving it must stop. Then we run into our old friend inertia. Bodies at rest tend to remain at rest, but all the powder burning behind the resting bullet doesn't know about that. It keeps burning and pressure rises. Sometimes we get lucky and the bullet starts to move and relieve some of that pressure, but in a worst case of a rough bore and/or soft bullet it doesn't, and pressure continues to build until something else lets go. Most of the time this will occur around the primer pocket and gas will be released through the flash hole, but we're talking about events that are taking place quickly (milliseconds); and if pressure rises at a rate faster than it is being relieved, a catastrophic failure is inevitable It has been theorized that many 'accidents" represent a combination of effects which combine, in worst case conditions, to produce a catastrophic failure. Robert Greenleaf (Rifle No. 146) presents convincing evidence to show that conditions rarely remain the same, and the condition of the barrel and throat combined with different bullet characteristics can produce markedly different pressure levels for the same load. This is certainly seen in this data where a series of eight shots of the same ammunition delivered pressures ranging, and steadily increasing, from 48,820 psi up to 82,120 psi, at which point the test was stopped. We can, from looking at this test data, presume that all rounds (except perhaps the first) displayed some degree of temporary bore obstruction, but that the bullet was blown out of the barrel. Fortunately universal receivers are capable of containing considerable pressures, and it is certainly possible that the pressure generated by the last shot would have wrecked a standard rifle.

One factor that cannot be accurately measured with this data is the possible contribution of fouling from the bullet itself. It seems reasonable to assume that some accumulated fouling was blown out on the fourth shot, which accounts for the drop in pressure at shot No. 5.

When the engineers were able to examine and expand the time/pressure curves produced during this test, it became obvious that each shot showed a pronounced drop in pressure very early in the ignition/burning cycle and, on the shot where the pressure reached 82,120 psi, it dropped to the baseline before resuming a climb to the stratosphere. It would be easy to think that the fire went out, but a more reasonable explanation is that the burning rate of the powder became even slower. We know that pressure is a major component of the burning rate of any powder, and it depends upon adequate pressure levels being reached and maintained. In fact, what is shown in this case is that the amount of gas being generated was not sufficient to keep the bullet moving. If pressures drop below some optimum level, burning slows down and is often incomplete. Of course there will always be a quantity of unburned powder from any shot, and this observation has led to some of the conclusions regarding S.E.E.

In order for the pressure to rise to catastrophic proportions some other adverse conditions must also be present. These involve the cartridge case, the bullet, chamber and barrel and need to be discussed individually.

Bullet pull: We know that an adequate amount of tension between the case neck and bullet is a prerequisite for uniform combustion. This term, called bullet pull, is independent of the firearm and is routinely measured in the factories. Crimps may or may not be used to increase bullet pull, but most centerfire rifle cartridges depend primarily on tension between the case and bullet. If you've ever committed the sin of firing a cartridge into which you have neglected to dispense powder, you know that the primer alone is perfectly capable of propelling the bullet several inches down the barrel. Pressure generated by a primer alone can be as much as 4,000 psi in a conventional centerfire rifle cartridge; so it is certainly possible, in a normal round, for the primer impulse alone to be sufficient to get the bullet moving before little if any pressure has been generated by the powder charge.

Chamber: In the area of the case neck there must always be some clearance between the case and the chamber wall, but if this area is too large there is little resistance and the bullet can be released with very little pres sure behind it.

Condition of the barrel and throat: The impact of conditions within the chamber and throat are difficult for the handloader to analyze, and a throat that appears normal under cursory inspection may be revealed to be rough and irregular when seen through a bore scope. Greenleaf's report (Rifle No. 146) details how pressure increased as the number of rounds fired through a test barrel grew larger. This can only be attributable to a deterioration of the throat and leade on that particular barrel. In this instance SAAMI standard barrels were used and showed no irregularities, and it was only when the same ammunition was fired in a 'field' barrel with more generous tolerances and wear in these areas that problems were seen.

Bullet hardness and stiffness: The shape and construction of the specific bullet used can be a major factor in the levels of pressure developed by any given load. Bullets undergo some degree of deformation as they enter the bore, and the force required for them to engrave the rifling and obturate to bore dimensions can vary considerably.

Temperature: We know that pressures tend to increase as the barrel heats up, and a round that produces perfectly normal pressures from a cold barrel might show signs of excess pressure when the barrel is hot.

Work presented here answers questions. Some of the findings support theories offered to explain S.E.E. some don't. We haven't, for example, seen any evidence to indicate that there is ever an explosion, and many authorities doubt that there is. Perhaps what we need is a better name. Taken to its most basic component, what we have is that most fundamental cause of catastrophic failures: a bore obstruction. The difference here is that the offender is the bullet itself effect rather than some external source is both predictable and reproducible in the light of this new evidence, but it is highly dependent upon a combination of factors that produce disastrous results. If one or more is absent, everything will probably turn out fine; but when all come together, pressures rise and, sooner or later, sooner or later, something will fail. While it would appear that slow-burning powders contribute significantly, until now we didn't exactly know what to look for. I think it's at least theoretically possible for a bullet to stop in a barrel if the other conditions are bad enough with propellants other than the slower grades.

Have you ever fired a load that you had used often and suddenly gotten signs of excess pressure such as difficult bolt lift or flattened primers, and then fired another that seemed perfectly normal? I think this happens with some frequency, and our normal recourse is to shrug our shoulders and also be a bright red flag waving in keep on shooting; h6wever, this could front of our nose that is telling us that something is wrong. In the light of these findings, it could be telling us that a bullet did a stutter step before it went on out the barrel. The question then becomes what should we do about it. My first suggestion would be a careful investigation of the condition of the bore, especially the throat or leade to see if there is any erosion or roughness followed by thorough cleaning. A chamber cast might be in order to get precise measurements. If the barrel shows obvious signs of wear or throat erosion, the cure is obviously to replace it or set it back and rechamber. If the barrel appears to be within specifications, however, a change of bullet or propellant may be enough to solve the problem. The importance of this information is that it explains, with laboratory documentation, what can happen when the wheels fall off in the worst way. It seems like such a reasonable answer to many of the mysterious ka-booms that good reloaders have had with good handloads, and it is something we all need to keep in the back of our minds in case we encounter something out of the ordinary. While the data here was generated using the 6.5x55 Swedish cartridge, the observations are not specific to that round. They could occur with almost anything.

[tomme boy]

So tell me again how this can not happen?

[Der Gebirgsjager]

Thank you for posting this very interesting article.

What I took away from reading it were more questions than answers. I wonder what is meant by a "non-canister" powder? Exactly what that is would seem vital information to the test cited in the article. Non-canister, to me, indicates a powder that is not normally available for commercial sale, and therefore not "tried and true."

The condition of the leade, throat, chamber, rifling--all listed in the article as being able to have profound effects on the pressure situation. From the photos originally posted and past experience with the Swede Mausers that were brought into this country I would think all would have been excellent. The Swedes rated the condition of these rifle barrels on a scale of 1-3, and changed them out at the end of the 2 rating (finding a 3 is uncommon), and the rating is recorded on the stock disc. So I would assume an excellent barrel, and fortunately for whomever will investigate this incident, the barrel seems to have remained intact. It would be interesting to know, and perhaps definitive knowledge, if there is a bulge in the barrel.

This incident puts me in mind of the blown up .38 special PPC revolvers of the 60's, where the standard loading of 2.5 gr. of Bullseye behind a 148 gr. wadcutter was claimed to be due to detonation of the powder rather than burning due to excessive air space in the loaded case. It was pretty much debunked by extensive testing in the White Laboratories, put down to double and sometimes triple loads, and is mostly unheard of today.

At this point it is really impossible to say what actually happened, but hopefully a thorough investigation will reach a conclusion. For now, I would play the odds and be inclined toward a double charge or more of powder.

Thanks again for the article, which is well worth the time to read.

[Hick]

I've enjoyed reading all this, and would like to add just one little thought. The shooter said the recoil felt normal. That alone indicates a major overcharge or pressure spike. Its a Physics thing. It takes energy to tear apart the rifle, and energy spent that way does not produce recoil. If the energy that reached the shooter was about the same, there had to be one heck of a lot of extra energy coming from somewhere to do the damage. Where that extra energy came from I have no clue-- but it had to be there.

[bruce drake]

I once blew off the top of the cylinder of a spanish-made Police Positive clone in 32 Long because I was reloading and then got pulled away from the powder charging steps to deal with a "family crisis" and then went back several days later to complete the charging of the cases. A double charge of Hodgdon 700X powder will definitely fit in a 32 Long case with a 100gr RN. It split the cylinder wall and the "blossoming" of the cylinder bent the top-strap of the pistol up more than a 1/4"!!!
Lesson learned. When I am charging cases. I complete the entire powder-charging run when I have time to seat a boolit in the cases in the same block of time that I'm in the man-cave.

Bruce

[CHeatermk3]

Well, 2400 is not a slow powder and cast boolits are easier to push through the bore than long-bearing-surface jacketed ones are.

supposedly it's (was) an excellent condition example, possibly never issued.

So, how's this for a scenario:
We don't know the condition of the bore/throat leade; was any effort made to get any copper out of the bore?
Unissued rifles should not have much copper fouling but not much if anything said so-??? questions.

Also, the left-handed shooter lost the end of his right thumb. was the rifle on a rest, with the off-hand resting on top of the action? Perhaps the rifle was held up by the off hand, sort of a benched-offhand position? Maybe the bolt operated by the right hand, the rifle's muzzle pointed down for a bit. Then, raised up to fire--with the powder positioned mostly foreward?

Now, what about ambient temperature-- so here's what I'm postulating--the primer lights, pushing the powder/boolit into the throat then boolit pauses at contact with rifling, meanwhile powder fuses into a compacted, plastic mass which then explodes?
I have had a primer-only ignition in a Mosin; the boolit stopped (314299/22BHN) with it's base in the throat and the nose/DBs in the rifling.

??

[tomme boy]

The main reason I brought up the SEE is because it can happen. VERY unlikely from a cast bullet because of how easy they can be pushed down the bore.

I am pretty confident that it was a OVER-charge that did this. But one has to take into account that the 6.5 cartridge and the M38/96 rifles seem to happen to them more often than other types of cartridges and rifle types. It can happen to any gun. And to anyone.

The ? of NON-canister powder is the powder that the ammo makers use. Sometimes it is the exact same thing as we use but mostly it is a special blend that they have made for their application.

If this guy has any more of the reloads, I would like to get ahold of them to see what he ACTUALLY was doing.

I myself have come close to having one of these. One was a 45 Colt using H110. It was by no means a light charge. But the throat on my Handi rifle was VERY LONG. H&R likes to run their throats like a Weatherby. LOTS of free bore. You could actually chamber a 454 Casull in it. And no NO one played with the chamber as I bought it new. It would hang fire all the way up to a max charge. I had to go to a Mag primer to get it to stop. This was a Accurate 45-310c.

The other was with a 91/30 I had about 10 years ago. It had a good bore but the throat was long and worn. SOUND FAMILIAR? Anyway it was with RL15 and a 174gr HPBT Sierra. I was seating the bullet out to get closer to the lands. Well that was a mistake. I started to get hang fires and I stuck a bullet in the bore about 2" down. When it did it all I felt was the bolt strike. Well I ejected that case and all of the powder turned into a solid clump. I was lucky it did not blow up. No other powder did this that I tried.

Edit. I also forgot I had my 308w do this with a 190gr cast and 4895. Temp was a HUGE factor using this with a reduced load. It got down to about 40 deg and I would get hangfires. It was very slight but it was noticeable. Adding a 1 gr of dacron and it took care of it.

[Dutchman]

The condition of the leade, throat, chamber, rifling--all listed in the article as being able to have profound effects on the pressure situation. From the photos originally posted and past experience with the Swede Mausers that were brought into this country I would think all would have been excellent.

".....all would have been excellent." Not at all. Incorrect assumption I'm afraid.

The Swedes rated the condition of these rifle barrels on a scale of 1-3, and changed them out at the end of the 2 rating (finding a 3 is uncommon), and the rating is recorded on the stock disc. So I would assume an excellent barrel,

I have a couple #3 in my safe right now. Not uncommon at all to see #3 bore condition rifles.

Just to re-align some thought processes about Swedish Mausers....

Not all that were imported came from military stores. Some that we see with a piece of tape across the butt comb with a number like 67 are those rifles that came straight out of military storage with the 67 indicating last inspection date. Many, but not all, rifles that came out of military storage were rebuilt prior to storage. Rebuilt in the sense that they had new barrels installed, in many cases new stocks & handguards and metal refinished with black Dulite black oxide treatment. New stocks & handguards were mostly beech post-1917 period. It is these rifles that most often are mistaken as being "un-issued" or called "minty". Not the case at all. They were shot to death and rebuilt.

Many thousands of m/96 were imported from Frivilliga Skytterorelsen (FSR) Volunteer Shooter's Organization. These rifles were sometimes fitted with diopter target sights but not always. The Swedish gov't approved the modification of loaned rifles to be drilled & tapped for diopter sights but many times they were not installed.

Add to these FSR rifles is the fact that military maintenance protocol was not followed. The brass disc meant nothing in FSR use.

I own a nice looking 1902 Carl Gustaf m/96 that was imported sans bolt, cleaning rod and front & rear sights. That's a good indication off the bat that it came from a shooting club and that it was condemned. That assumption was proven when the barrel was inspected. It was shot out to the point that there was no rifling whatsoever remaining in the first half of the bore. Eroded would be the correct term. I installed front & rear sights, a cleaning rod and installed a bolt. I shot it with 140 gr Lyman Loverin @ .266". Tumbled like a football end over end even at 25 yards. My one single new m/96 barrel will be installed on this rifle. The trigger & sear on this rifle trip at less than 2 pounds. Those parts were "worked over" somehow to yield the lightest triggerpull I've ever felt on a Swedish Mauser. Its still a 2 stage trigger but it lets go with a cat's breath amount of pressure.

How this rifle escaped a new barrel is the great mystery. It has never been rebuilt or refinished. It is 100% original to 1902 manufacture with the tightest stock-to-metal fit of any Swede I've inspected. I paid $75 for it with the missing parts without seeing the bore.

Another of my m/96 is one that cost $40 in 1988 due to the fact that it had been drilled & tapped on the rear bridge for diopter sights. (Paragon Sales Joilet, Illinois). The bore is very worn, beyond what you would feel could be an accurate shooter. At 50 yds it put 5 rds of the same .266" Loverin cast bullets into 1" with none of the holes touching. At least half the bore has rifling with edges but the breech end of the bore has very rounded, almost non-existant rifling. I had installed diopter target sights on the rifle for this one last test firing to see how it would group with a known accurate cast bullet load. In a better rifle that load would put 4 out of 5 in one hole at 50 yds so opening the group to 1" with non touching might seem minor but the MOA would've been over 2" at 100 yds, likely greater than 2". I'm torn over what to do with this rifle as I have only one loose new m/96 barrel that came from Samco for $70. They are now priced about $300 each for the spare Carl Gustaf m/96 barrels. (and near $300 for Lothar-Walther barrels).

This m/96 that came apart appears to be a 1903 with serial number 125502. Hard to see but that's close. Stock is beech so its a replacement stock. Stock also appears to have been sanded as the wood edge around the disc hole is slightly rounded. The stock color is not "Swedish". The one dead give-away that the stock has been refinished (in USA) is the handguard. The two ridges on the handguard between the receiver and rear sight are rounded. They should be sharp. Meaningless observation but its what I see when I look at it.

See photos of the 1902 m/96 mentioned above. Stock is French walnut.
http://dutchman.rebooty.com/wood_to_metal.html

in excellent condition, may never have been issued.

This quote is significant in that whoever assessed the condition of this rifle was inexperienced in the area of Swedish Mausers. It most certainly was issued. And it was a sanded/refinished stock, most likely in the USofA. While this has no actual merit on the causation of the incident it does reflect the eyes of the person describing the incident. How many other points of this description are in error as are the observations on the overall condition of the rifle? From a technical and objective perspective I must assume all the observations on this incident by the participants are skewed to the point of being useless. Forensic examination excludes uninformed opinion, though may include anecdotal observation when technically astute.

The barrel didn't rupture. Instead it sheared the upper locking lug causing the receiver ring to break apart. Abundant vaporized brass at this point, the upper locking lug.

Interesting that only the one locking lug sheared. Makes me wonder if there was equal lug contact with the receiver lug race.

I agree with those who suggest handloading error: double charge 2400.

Dutch