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Discussion Starter #1 (Edited)
This previous sticky might deserve to stay on top?

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The Armourer
Posted - 12/14/2005 : 03:43:10 AM
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M96, 1917 production, anyone else had this sort of failure on firing pretty ordinary ammo?
Cheers
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Tanker
Posted - 12/14/2005 : 07:03:37 AM
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I've never heard of an M-96 doing that before.
Dave



kriggevaer
Posted - 12/14/2005 : 12:28:48 PM
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Have never seen one like that. What kind of ammo? Factory or reloads?



jp
Posted - 12/14/2005 : 2:23:38 PM
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Could this be from lubricated cases or oil/grease in the chamber? Perhaps that would allow too much rearward thrust???


Dutchman
Posted - 12/14/2005 : 3:24:57 PM
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We need some additional information.

Do you have photos of the receiver?
What ammo, exactly, was fired in this rifle?
Has this rifle been subjected to hot handloads?
Was the primer blown out of the case?
Do you know the diameter of the primer pocket?
Was the shooter injured? (we hope not)



BigBill
Posted - 12/14/2005 : 4:24:50 PM
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It looks to me like the bolt was blown back.



houstonfrank
Posted - 12/14/2005 : 5:46:56 PM
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I have never seen that kind of failure in any bolt gun. I do not understand why the case did not rupture although the primer evidently blew out. It seems to me to have been a progressive thing. The bolt/gun had been subjected to excess pressure before and possibly set the lugs back or cracked them. Were there prior rounds fired from the same lot? What did they look like?



Spanner
Posted - 12/14/2005 : 6:23:23 PM
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I remember reading somewhere about a receiver blow-up of a Swedish Mauser under carefully controlled conditions. The testing was done by either Norma or Lapua. Each round was chronographed and pressure tested and just after the pressure spiked, the rifle blew up. After shooting quite a few rounds normally, this happened very quickly. I recall it was discovered the cause was a build up of copper fouling in the barrel that increased the pressure.
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Edited by - Spanner on 12/16/2005 05:02:43 AM



The Armourer
Posted - 12/15/2005 : 04:07:24 AM
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The story with this is that it was in as-issued condition, good but not perfect order. Owned and used by a very experienced target shooter. He was using handloads, mild with a 140gn pill. On his 3rd round for the day, he fired and a small puff of smoke exited the action. He went to lift the bolt and it came straight back with out lifting. From there he bought it into our workshop. Case and both locking lugs were still in the reciver. We removed them, case showed no excessive pressure signs (obviously the primer had come out, basically because the bolt ceased to support it)

As we were at a loss to explain the failure we sent the bolt for testing, the report said that the bolt was of high carbon steel, and rather than being heat treated and tempered it had been case hardened and (obviously) high carbon steel cased hardened results in it effectively being glass hard all the way though, hence the failure.

We have no reason to believe that the heat treating happened anywhere other than at the factory or during a rebuild/FTR, so was interested to see if there are cases of other bolts being either made of the wrong material by mistake, or heat treated by the wrong method.
Pic below of the case in the reciever with the edges of the locking lugs holding it in place.

http://old.gunboards.com/uploaded/the armourer/200512154448_MVC-001S.JPG
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swede
Posted - 12/15/2005 : 05:04:17 AM
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I am no expert on heat treating , but someone has their information mixed up . Case hardening is a surface treatment that only goes .010" to .020" deep & would not result in it being hardened all the way through , much less glass hard all the way through . I do not know what process the Swedes used to heat treat their bolts , but I have never seen damage like that before . The Swedes had rigid quality control of their parts & I doubt that the problem resulted from the Swedish end . It seems to me that someone has tampered with that bolt in the many years since it left Sweden or fired hot loads on it before the present owner got the rifle . No way to prove it one way or another .



klempner
Posted - 12/15/2005 : 07:51:21 AM
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I had a M-63 split the receiver (sorry the pic's are on another machine)this happened when the primer blew, the gasses went into the mag well and split the stock in half, it ripped the reviever top. the bolt stayed in place. It happened from a bad lot of RE 22 (head the warning on the web site if you shoot RE22). ALWAYS WEAR YOUR GLASSES.....



brimic
Posted - 12/15/2005 : 10:40:11 AM
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I saw a picture of a blown up 96 on Parallex's site a few years ago where a novice reloader had filled the case completely full of bullseye (I guess he figured that if a little of the powder was suitable for pistol loads, a lot of it would be good for a rifle) It sprung the bolt out of the receiver, sheared both lugs and twisted the receiver. Remarkably the shooter was not hurt.



Quaritus
Posted - 12/15/2005 : 3:22:07 PM
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Casehardening high carbon steel could in fact cause the part to be brittle. Casehardening is used on generally low carbon steel and iron to give the surface (case) hardness and wearability, about .010" as stated above. This is to make the part less expensive, more easily machined, and to retain the toughness and relative softness of the core. In doing so, carbon is introduced at the surface of the part at the critical temperature (ie, cherry red and packed in charred bone) for a period of time to allow the carbon to be absorbed by the base metal. So if the base metal is already high carbon and you add more carbon at the surface, and then quench and leave in a hard state, you may have "over hardened" the piece. High carbon steel is therefore through hardened, without adding carbon to the alloy (doesn't need it) and then tempered to reduce brittleness and increase durability. That said, I would be very surprised to find that this happened at the point of manufacture in Sweden as steel alloys and heat treating are their specialty. Alot could have happened to that bolt in the last 90 years. And, thank goodness, your friend is very lucky.



mman
Posted - 12/15/2005 : 4:12:12 PM
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Mausers, ALL Mausers of this era should be made from low carbon steel. They are surface hardened for wear resistance. This bolt therefore doesn't add-up. But I suppose a bolt made as discribed could fail like that?

There is no evidience to suggest that Swedish Mausers are any better than German. Indeed evidience of the opposite might be suspected. There are a bunch of CG rifles that had there receivers replaced with spare Mauser Oberndorf receivers. There must have been a reason these CG receivers had to be replaced?

Jack
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email at [email protected]



BigBill
Posted - 12/16/2005 : 6:26:48 PM
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I wish i was still working we had one of the best metalurgery guys on the planet he would know why it broke like that because thats all he did was find out why things break in the field. I worked in one of the most modern product reliabilty and failure analysis labs in the country. Being retired i sure miss the perks.

For many years the swede's manufactured the best steel on the planet. Nobody came close to the quality to the quality of there steels. Since most of these rifles are well used and passed thru many hands its the people who owned it before and what they fed thru it that could be the problem too. Shooting hotter loads does take its toll sooner or later.



jim in Oregon
Posted - 12/17/2005 : 09:16:38 AM
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I am skeptical that the bolt-safety assembly or the rifle was in any way responsible for this destruction.
Not like the components had been force matched by some dim-witted elf.

That 1917 Swede M96 rifle had probably been used and shot by dozens of Swedish soldiers over nearly 50 years.Literally thousands of rounds.
In addition, I'd expect it was examined and refurbished by trained Swedish armourers at least three of four times during it's service.
This is not some 'original defect' issue in the steel choice, mettalurgy, or fitting of the rifle together for service.

Something else caused this break apart.
I would say it was improper ammunition or oil-grease in chamber-locking lug area or a combination.
Unfortunately, some shooters will not -fess-up' when they have a rifle destruct and so the forensic folks chase their tails when the root cause is opertaor error, maint screwups or BAD ammo-component choices.

Possibly a previous owner had overstressed the rifle receiver-bolt and the present owner shooter experienced the end result of trying to make an M96 shoot velocities of the 7MM magnum of some previous shooter-reloader (idiot).



jim in Oregon
Posted - 12/17/2005 : 10:16:02 AM
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One other observation, and again asking a question of armourer from his recollections which hasn't been covered:

AMMO??
From the picture, the brass is metric in mfg origin, evinced by the comma on the stamping of the case..6,5...55..and then about the only discernable stamping on the case head is a 'D'...

It isn't Lapua or Norma..and certainly isn't american made Remchester etc.

What was the ammunition fired in this case and spec on components?
Factory or reloaded and most importantly..spec of components..jim



mman
Posted - 12/17/2005 : 11:01:32 AM
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Originally posted by BigBill
For many years the swede's manufactured the best steel on the planet. Nobody came close to the quality to the quality of there steels.
myth, Myth and more MYTH. Oft repeated but still myth.

Just like the guys who defend the crap steel in some Spanish Mausers because Spanish steel(swords) of several 100 years before was the best.

There is simply zero evidience that Swedish Mausers were made from steel superior(or worse) to other Mausers. Indeed as suggested in my post above there is evidience to the contrary. The steel in the Swedish Mausers might have been provided from several sources. Does anyone KNOW that that all or any were made from domestic steel?

Another point. The customer had a choice of materials on contract Mausers. Webster in his Argentine Mauser book details these choices. Argentina chose the best for their barrels for instance... In the case of the M1891 Argentine, not one single rifle(out of 230,000 rifles and 33,500 carbines) failed proof. How much "better" can you get. Can the "Swede's" claim as much.

Low carbon steel was/is not rocket science even in 1900. Even in normalized condition it was plenty strong. Surface hardening was for wear only. The Mauser was strong enough by design and did not depend on superior material in any way.

(But it must be "good enough". Defective material did surface. QA was necessary. 40,000 M91 bolts were replaced by Loewe for free because of the possibility of poor material.)

Millions upon MILLIONS of Mausers have served for over 100 years. Reports of failure, especially for material defects, ard so rare that they cause a banner headline when they do happen. MILLIONS of these rifles were manufactured under the stress of war and upset of material supply, yet we seldom hear of failure...

Now here we do have a failure of a M96. I have seen a couple others(set back). I have also heard that the Mauser was finally removed from Swedish service becasuse of several failures, one resulting in the death of a young officer....? If so, so much for superior steel?

I don't really know why this bolt failed or if it is the original bolt or if it had been messed with, or if, If, IF.... But whatever it's not a GOOD sign. If I had any Swedish Mausers in my service, I'd get out my 10x inspection lope and the magnaflux....

One more point. Thr re-hardening of Mausers sometimes suggested may be one of the most dangerous practices possible. Nothing could be worse than TOO hard(maybe evidienced by this accident). I wonder if someone tried to make this bolt "better"? Much better to be too soft. In that case progressive failure(the "normal" or usual failure mode for the Mauser) can be caught with proper inspection and gauging.

I'm also somewhat skeptical of the "high carbon" steel report unless it is an aftermarket(POS) bolt.

On the other hand. I can not say that Sweden did not employ a different type steel/heat treat than the low carbon typical in ALL other Mausers I am aware of. If they did use "high carbon steel" with some complicated treatment, I'd still be hard pressed to say that it was in any way better. Different yes, better or "best", no way....

Jack
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email at [email protected]



BigBill
Posted - 12/17/2005 : 5:11:02 PM
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mman; Your going to have everyone scrambling for the newer husqvarna mausers now?? Time is a factor too time does take its toll. Maybe the older ones are too old to shoot now? Just kidding these mausers have been around for a longtime and i'll check mine out and still shoot my swede's and german mausers and enjoy them till i pass on.

My Dad was a prototype/repair machinist for over 50+ years and he always told me the swedish steels were the best quality. Recently its the japanese steels with their electric furnances back around the 70's & 80's I believe it was. Their way of manufacturing steel(process) was so good that Carpenter Steel here in the US got electric furnances too. It could of been the swedish manufacturing process that made their steels so good.

I restored and repaired dirtbikes for many years. I never had to weld or repair a frame on a Husqvarna dirtbike. I later found out the swedish frames were all made out of chrome moly steel. I can't say that for jap bikes I welded and repaired many frames and they were newer frames than the swede bikes were too. Even the jap street bikes with two stroke injection motors had bad frames too I welded many of those too because of stress cracks in the tubes. But i never welded any swede frames and again they were much older could it be they had a better quality steel? Hmm.....



Hag
Posted - 12/17/2005 : 10:39:19 PM
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What is the "mild pill", "pretty ordinary ammo" handload that caused that big black hole in the case head? It appears something got into that case that caused colossal pressure. Wrong powder, too much powder,or perhaps a foreign object. Witnessed one other firearm blowing up similarily. It was discovered that a smaller case had been stuck inside the case being loaded. It was aluminum and fit like a sleeve.



mman
Posted - 12/18/2005 : 11:15:35 PM
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BigBill,

I have no doubt that most Swedish steels are among the best. At the turn of the Century they aquired the reputation for the highest quality gauge blocks, and maybe tool steels. I had Swedish gauge blocks in my measurements lab at the US Army BRL/APG . They were beautiful, a work of art. But no better than those by P&W.

According to Dana, the Swedes purchased the tooling for the Mausers from Loewe in Germany. (Late delivery was the reason for the Mauser made 96's in 1899/1900) That says something.

I'm also a pilot and student of military aviation. I recall that the Swedish aircraft industry was not without their early problems. I seem to recall that either their B17 and/or B18's(NOT like the US with those numbers) suffered from material defects(specifically steel) that led to delays in the 30's and 40's....?

But again, low carbon steels were simply not rocket science. Better is the enemy of good enough and too much "better" in this case is simply stupid. Low carbon steel is low carbon steel, not hard to make correctly and "better" simply does not compute. The only countries who seemed to have had a material problem with their Mausers were the Spanish and the US...... Well we still have those CG's with replaced Oberndorf receivers. I admit they are not fully understood but they do suggest questions as to why.

Not a big thing really. I wouldn't let one broken bolt ruin my Swede shooting. But I might tend to keep a close eye on stress points on all my rifles, Swede and German and etc.

Regards,

Jack

PS. Those Japanese bikes are pretty hard to beat. My $10,000 04 GSXR-1000 will suck the doors off one of those little red $600,000 Italian cars with the little horse emblem.....
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email at [email protected]



Gunsisme
Posted - 12/19/2005 : 2:48:44 PM
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Actually case hardening only goes .001 to at max .002 deep which leaves a very soft core. This looks to be a bolt that was hardened and not tempered or stress relieved as heat treating requires. Not tempering a harddened piece of steel will leave it glass hard and brittle



swede
Posted - 12/19/2005 : 5:15:18 PM
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I think you have been badly misinformed about case hardening . As a machinist for the last 40 years , I have case hardened thousands of parts over the years & the standard is .010" to .020" deep . We normally leave parts over size from .005" to .010" for finish grinding case hardened parts . These parts normally check 68/72 on the 30N scale . Indeed these parts have a soft core . Alloy & tool steels are used when hardening is needed all the way through the part .



Mike442
Posted - 12/19/2005 : 10:48:57 PM
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I agree Swede. If memory serves me right, case hardening on automobile engine crankshafts goes at least 0.030 to 0.040 inches deep.

I just hope this doesn't happen to anybody else's Mauser. In my 50 years plus of shooting, I only had one incident like that. First shot out of a box of commercial ammo (so I thought since it was in a new Remington commercial ammo box) that had been given to me. Blew my M1 Garand to pieces and I was very lucky, I didn't get a scratch. But there sure were a lot of M1 Garand parts lying around. After closely inspecting the rest of the ammo in the box, I discovered they were reloads. Disassembled a few and discovered they had been filled with pistol powder. Needless to say, I have never accepted ammo from anyone again. That was about 30 years ago.



Ed Novak
Posted - 12/19/2005 : 11:36:35 PM
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Reloading is not "rocket science", but it can become just that when things aren't put together just right. Preaching to the choir maybe, but I've been reloading for 40 years and I still don't quite trust meself all the time. Mike442 makes another very, very good point about reloads. ed



BigBill
Posted - 12/20/2005 : 6:36:29 PM
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Mike442 and Ed; You guys are so right about someone elses reloads. I had a neighbor bring over his buddy's reloads and said you gotta try these. There sitting on my shelf for about 5 years now I'm afraid to try them. I never shot someone elses reloads yet and it was always my gut feeling not too. Its a Very Good point!!!!!!!



Ron T. B.
Posted - 05/08/2007 : 8:05:32 PM
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I read and article in which the author purposely and incrementaly overloaded a swede 96 and a 1917 enfield. As I recall the powder used in both was 3031. He increased the load by 2 grains until he saw obvious pressure signs. The case head failed in both rifles. The extractors were blown off and hot molten brass bearing gas blew backthrough the actions. In both cases the reciever ring and bolt, excepting the extractors, were undamaged.



Vladymere
Posted - 05/08/2007 : 8:54:26 PM
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I have seen these same photos before floating around the net. At this point I think that no one knows the truth abouth this bolt.



Smokepole50
Posted - 05/08/2007 : 10:23:49 PM
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My guess would be a double loading of some fast powder intended to be a light target load. This happens a good bit with pistol hand loaders. 4.8 grains of Bullseye makes a nice 45ACP load but 9.6 grains will blow you gun apart.



Big commander
Belgium
Posted - 05/12/2007 : 06:24:01 AM
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Originally posted by jim in Oregon
AMMO??
From the picture, the brass is metric in mfg origin, evinced by the comma on the stamping of the case..6,5...55..and then about the only discernable stamping on the case head is a 'D'...
It isn't Lapua or Norma..and certainly isn't american made Remchester etc.
What was the ammunition fired in this case and spec on components?
I realize that this is an old post but the case is a "Norma" case. The "D" is in fact an "a", the last character of the word, one can see the "n" also and a good part of the "m" (in the indent). Not that all this is very important now. IMHO it's impossible to say why the lugs gave away but I'm a strong believer in "bad reloading habits from previous-owners-who-shy-away-after-they-realized-they-goofed".



Xwingnut
Posted - 05/12/2007 : 07:39:09 AM
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Case hardening was not used on the bolts. It would have left the typical color molting pattern and buffing the bolt to a luster finish as all Sweds are would not have been possible. The depth of case hardening is .001 to .003.

If I were to guess as to what caused the failure I would have to consider the history of all Sweds, this is the first one I have heard of doing this. If it were caused by workmanship it would have happened long ago.

This was caused by high pressure loads or load- bore obstruction, wrong powder, over crimping etc.

I have seen a bolt that had been worked on by someone who left a file mark in the corner of the lug and bolt body. Like glass having a scratch in it that becomes the starting point for any failures.

Someone mentioned getting out their 38 and not using the 96, if you want to check you bolt buy a die penetreant kit and check the lug to bolt body areas for cracks. I would not be worried about my sweds (1900 Obern and a Husky 42).



Xwingnut
Posted - 05/13/2007 : 07:08:43 AM
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One other point, the engineers always design the bolt to be lower on the hardness scale than the reciver, reason is economic, its easier to replace the bolt than the reciver. I the bolt was case hardened or heat treated to a higher RC scale # number than the rec. then it would wear the raceway and lug locking channels fast. The best case would be to heattreat the rec and bolt to the same number.



Dutchman
Posted - 05/13/2007 : 6:41:56 PM
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I'm glad this message thread was brought back up.

I'm going to make this a sticky note for a while. Everybody/anybody who shoots a Swedish Mauser (any small ring Mauser) needs to know this kind of failure happens and when it happens the shooter is often injured.... sometimes severely... sometimes injured to death.

Dutchman



SWEDISH K
Posted - 05/17/2007 : 05:39:17 AM
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I have seen that before...

But only when some fool have removed the wooden projectile of a Swedish blank firing round and replaced it with a FMJ 6.5x55 (and used the powder from the blank firing round).

That is highly dangerous!!!!!!

The m/96 was a very popular rifle for hunting here in Sweden some time ago, and also popular to convert into "hunting rifles". The old gentlemen who had these, sometime were parsimonious and used FMJ rounds from "the Crown". They simply file a cross in the tip of it and hunted... Not to recommend, sometimes the bullet disrupted and reminders were left in the barrel, and when the next round was fired the barrel was blown... Some of the gentlemen came up with the idea to remove a blank firing bullet, and replace it with a ordinary one. They only tried this once! I promise.



Dutchman
Posted - 05/23/2007 : 5:30:35 PM
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Originally posted by SWEDISH K

The old gentlemen who had these, sometime were parsimonious and used FMJ rounds from "the Crown". They simply file a cross in the tip of it and hunted... Not to recommend, sometimes the bullet disrupted and reminders were left in the barrel, and when the next round was fired the barrel was blown...
What you're saying is the lead core was blown out through the hollow
nose leaving the jacket stuck in the bore thus creating a bore obstruction. This has also been known to happen in the U.S. with military .30-06 ammunition in the hands of very cheap shooters. Open ended bullets will most certainly blow the lead clean through the jacket in many cases. We don't often consider this but it is a viable cause for such a failure.

Dutchman



Andy_P
Posted - 08/01/2007 : 2:15:03 PM
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I've done a wee bit of proof testing myself, and have never been able to produce results that saw lugs broken off and the case left essentially intact. For example, a Carcano (wrongly believed to be inherently weak), survived a full case of Unique behind a 160gr bullet. The case head was blown to bits as was the extractor, the bolt had to be hammered open, and the front half of the cartridge required a lot of effort to remove - but the bolt lugs appeared untouched.

This is a case study on how false rumours start - no information of substance exists on the rifle in question, just pictures, a situation which invites embellishment at each stage of it being passed around. A recent issue of Handloader magazine claims lug setback on the first firing of a M96 due to "soft steel". These myths are a real industry.

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Andy
 
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