Experieces with Gun Blow-Ups and other catastrophic events

31 August 2007, 09:11

RIP

For Blaser fans:

The Blaser 93 Blowups circa 2003:
The Norwegian handloader in one of these kabooms had used 6.5x68 to make 8x68 brass (or some similar neckup only), the case split, probably was not an excesive load, just a case split:

Gas escape disintegrated the plastic housing on the Blaser bolt and thar she blew. Since then the recalled guns have had the plastic bolt part replaced with an aluminum one, and declared safe by Blaser.

31 August 2007, 09:24

RIP

The reloader who lost his shooting eye and had some of his skull replaced with titanium, now prefers a different rifle action

31 August 2007, 09:26

RIP

A luckier ex-Blaser user:

Where are those pictures of the Eargeschsplitten Tikka barrels?

31 August 2007, 09:55

Macifej

Not buying any of it RIP!

Case splits don't just happen!

Something precipitated the case failure......something not too bright!

31 August 2007, 10:00

RIP

Maybe it was old hardened brass that would not have split on firing if it had been annealed before necking up?

Hot gas does mess up plastic bolt parts pretty quickly.

31 August 2007, 10:25

Macifej

Yes and Yes!

Even with a plastic bolt shroud I doubt this kind of failure was caused by a split case. I smell a big rotten salmon!

Seems there are a lot of yahoo's playing in the chemistry lab who haven't read their book first.

31 August 2007, 11:34

Indlovu

I had a similar experience when i inadvertantly fired a 243 round through my 308. sounded like a squib load, but no damage and a perfectly necked up 308 shell marked 243.

quote:
Originally posted by Robgunbuilder:
I made the mistake once of shooting a .257 weatherby and a .338 win in the same session. My buddy handed me a .257wby and I stuck it in the .338. It fired with a dull report and out popped a perfectly fireformed .338win with a .257 weatherby headstamp. Scared the crap out of me when I realized what had happened. No damage to the barrel from that .257 bullet skipping down it as far as I could see.-Rob

31 August 2007, 17:19

jstevens

I have never seen a blowup in person, but was at the range a couple of years ago, watched a man shooting an old Mauser that was either a 7.65 Arg opened up to .30-06 or an 8x57 opened to 8-06. He was shooting factory ammo and tossing the cases out that were made into almost a straight wall and were split and he didn't even notice it until I picked one up and showed him he had a problem.

31 August 2007, 20:57

wildboar

Several years ago, with a friend, at the range, we were zeroing a couple of rifles; I was starting to shoot a BAR cal 7 RM (not mine), and he handed me a box of 7x64. I put a round directly in the chamber, I closed the bolt and pulled the trigger. I will never understand why, but the rifle shot; I felt a big blow of gas on my face, neck and arms. The (steel) receiver opened up in the lower part for about 1.5 cm. letting fall the trigger assembly, but I wasn't injured and the rifle had no real damage. We only had to clean it deeply and carefully clamp the receiver in a vise to the original width. That event taught me that one can never be too much careful.

31 August 2007, 23:08

Snugge

Mmmmm... oops!

quote:
Originally posted by Jim Manion:
Here's one recently caught on video

http://shock.military.com/Shock/videos.do?displayContent=146543&page=3

That's going to leave a mark!

31 August 2007, 23:15

Snugge

The Swedish military have performed tests on obstructed weapons.

http://www.testfakta.se/Article.aspx?a=16350

Unfortunately for you who don't speak Swedish, it's in Swedish...
Just click play on the different weapons and presto, the videos speak for themselves.

2 rifles stick out, you will see which.

/Snugge

01 September 2007, 01:13

jeffeosso

Wow, we have finally found an area related to bigbores that scott might have real experiences..

I mean, he seems to be the current king of blown primers

quote:
Originally posted by Robgunbuilder:
... questionable reloading practices. There is undoubtably a list of do's and don't that could be compiled.

quote:
Originally posted by ScottS:
I have blown a great many primers ie case head in my time though. .. The rifles, once cleared, kept right on firing.

quote:
Originally posted by ScottS:
At 80,000 psi I would have blown primers, if nothing else! More likely I would have a ruined rifle... \....Scott

01 September 2007, 01:29

walksfar

quote:
Originally posted by 400 Nitro Express:
quote:
Originally posted by Robgunbuilder:
Speaking of Lore, I was taught that minimal muzzel thickness must never be less than .125" each side of the hole" by the Great Mr. Selner a NJ gunsmith who I apprenticed with many years ago.

I've included the above quote in regard to your subsequent question about doubles, because it's a point worth making. A few of the current lower end doubles might well have that much wall thickness, but most double rifles don't, and many are nowhere near that. Most are under .100". For example, the last Holland Royal .465 I measured was just under .090", and a friend has a Dominion .465 that is .086". Heym's new Model 88B in .450/.400 with 26" barrels will be 15 mm at the muzzles, or .090" wall. I measured a couple of current Chapuis in 9.3X74R recently that went .522" and .524", or .078" to .079" wall thickness.

quote:
Originally posted by Robgunbuilder:
Can anyone confirm the English double rifle story where supposedly the use of monometal bullets ironed the rifling to the outside of the thin barrels? I had heard this occured on a Holland and Holland or some similar high end gun but can't confirm it.

I got it direct from Holland when I was in their shop in 1992. A customer ordered a new .465 Royal and stipulated that he wanted it regulated with monolithic solids. Holland had had enough rifles come through with rifling on the outside of the barrels by that time to figure out what it was from, and refused to be responsible for what might happen. By the time the regulator got finished with it, the rifling imprint on the outside of the tubes was severe. This was a new rifle, not yet finished (in the white), with barrels of modern steel.

The issue has to do with the wall thickness necessary for a nice double, and has little to do with old vs new steel. .125" is fine for a single barrel rifle, but it makes for a clunk of a double.
----------------------------------------------
"Serious rifles have two barrels, everything else just burns gunpowder."

Just for reference: I measured my .500 3", and it has walls around .110
I don't think I'd want them any thinner.

01 September 2007, 17:17

RIP

My Merkel Safari 470NE has muzzles that are .706" diameter identical twins.

That would be .1155" wall thickness in the grooves for a .475" bullet. Round it to .116".

The same muzzle diameter in a 500 NE with .510 caliber bullet would result in a wall thickness of .098".

I'll bet the Merkel 500 NE without the lead weight in the butt would be a well balanced and lively double. I want one.

I have not measured them, but I have been told that the Merkel 500 NE has the same barrel profile as the 470 NE. That should be fine with the 40KPSI or less loadings, since the barrel steel is "Krupp Stahl."

01 September 2007, 17:59

RIP

I could not find any pictures of rifling on the outside of the barrels of double rifles in the Graeme Wright book. I must have seen that picture somewhere else. He does however discuss in a matter-of-fact way, the inferiority of the steel used in 100-year-old double rifles, as does Alexander Gray.

01 September 2007, 19:11

RIP

Bro' lawndart:
What ever happened with the Sako-Tikka catastrophe discussed on the Gunsmithing forum in 2004?
Was this a case of modern steel gone bad, really bad?

01 September 2007, 20:22

MLG

Here is another interesting site.

This Swedish mob decided to test some rifles to destruction. They blocked all the barrels and then fired them.

In this test, the Blaser and Howa fared the best, followed by Tikka T3, Sako etc.

Don't think I would like to have been anywhere near the Remington or A-Bolt though!

http://www.testfakta.se/Article.aspx?a=16350

01 September 2007, 20:52

Big Bore Boar Hunter

quote:
Originally posted by RIP:
Bro' lawndart:
What ever happened with the Sako-Tikka catastrophe discussed on the Gunsmithing forum in 2004?
Was this a case of modern steel gone bad, really bad?

If my memory serves me, it was a bad lot of barrel blanks that were improperly heat treated that caused the problem.

John

01 September 2007, 23:27

mete

I don't ever remember hearing exactly what the cause was but certainly it was a bad batch of barrels.The worst part was Beretta didn't say a word even though there was a recall !

02 September 2007, 06:53

RIP

quote:
Originally posted by MLG:
Here is another interesting site.

This Swedish mob decided to test some rifles to destruction. They blocked all the barrels and then fired them.

In this test, the Blaser and Howa fared the best, followed by Tikka T3, Sako etc.

Don't think I would like to have been anywhere near the Remington or A-Bolt though!

http://www.testfakta.se/Article.aspx?a=16350

They must have gotten the sample Remington and Browning rifles from a bad batch too. Luckily the Blaser and Sako products for those tests came from the nondefective batches of those rifles.

02 September 2007, 07:07

Macifej

Is the former Trabant factory making rifles now or what? Are they using bamboo for barrels? Very good production rifles just aren't that expensive........

03 September 2007, 20:09

Robgunbuilder

Anyone have any data on Fluted barrels? I've seen some pretty deep fluting on high pressure varmint guns and always worried if the gunsmith who did the work calculated the depth and what std he used. Personally, while I've fluted barrels a few times, I kept things shallow.-Rob

04 September 2007, 00:57

RIP

They say ask Krieger about the stainless alloys and about barrel fluting.

Dan Lilja fluted a stainless .375 barrel for me and it ended up as a No.6 contour to be agreeable to all. Pretty fat. I decided then it was a nice experiment, but I would rather stay away from fluting henceforth.

Only makes sense on a varmint rifle for the micro-calibers to add a bit of increased heat loss in P-Dog-Town, IMHO.

04 September 2007, 03:23

Big Bore Boar Hunter

quote:
Originally posted by mete:
I don't ever remember hearing exactly what the cause was but certainly it was a bad batch of barrels.The worst part was Beretta didn't say a word even though there was a recall !

Beretta contacted all of the rifle owners individually and they had a blurb on their website. All in all, it was kept pretty hushed.

John

04 September 2007, 03:27

Big Bore Boar Hunter

quote:
Originally posted by RIP:
They say ask Krieger about the stainless alloys and about barrel fluting.
.

To my knowledge, Krieger is the only mfg to post a warning about stainless in sub-0 atmosphere. No where on their website do they post a why. Not being a metalurgist, the only thing I can think of is thermal expansion my be such that barrel constriction may be an issue.

John

04 September 2007, 04:00

Robgunbuilder

I have to say that in the case of old english double rifles operating at <40KPSI generally and with 22-26 inch barrels, I'm sure the muzzel pressure is low enough to provide some safety margin with .090 muzzel wall thickness. Easily calculated in fact. I for one would bet a Lott or Ackley would bell or crack a barrel of such a thickness.
Interesting point too about stainless steel fluted barrels. When I did mine, after I fluted it I sent it out for high temp stress relieving just as a precaution. I've never tried cryogenic stress relieving as I have heard some mixed results stories about it.-Rob

04 September 2007, 05:28

Macifej

quote:
To my knowledge, Krieger is the only mfg to post a warning about stainless in sub-0 atmosphere. No where on their website do they post a why. Not being a metalurgist, the only thing I can think of is thermal expansion my be such that barrel constriction may be an issue.

That warning was for their 410 or 416 stainless material. Likely because of rapid loss of ductility at low teperatures. IE - The stuff becomes brittle. Not all stainless steel behaves this way. There are all kinds of materials suited to barrel making most of us have never seen. $$$$$$$$

04 September 2007, 22:44

Robgunbuilder

I'm not a mechanical engineer so my analysis may be flawed,however, I believe that when we are discussing a barrels resistance to pressure based deformation( gaseous vs a fluid in the case of firearms., that this is best decribed as Hoop Strength. Clearly the thickness of the barrel, its materials of construction(alloy) and temp effect the Hoop strength and that strength varies by the alloy, contour, length and thickness of the barrel at any
given point. Obstructions can clearly cause the hoop strength to be exceeded and We probably need to be extremely cautious of the use of thin walled barrels with high pressure loads. Real Big Bore guys pay attention here as your trading off hoop strength vs weight reduction often when trying to build a gun you can carry. Would a carbon fibre wrapped barrel solve this problem? Powders with
burning characteristics resulting in high rapid peak pressures should also be avoided. So what are we to do? I for one have always been in favor of firing PROOF Loads in any new big bore. I proofed the .600OK on a CZ550 with loads calculated to reach 85 KPSI and fired two through the gun, then took it apart and checked all the original measurements before I ever shoulder fired it. I'm still thinking thats a darn good idea.-Rob

04 September 2007, 23:04

KSTEPHENS

quote:
Originally posted by wildboar:
Several years ago, with a friend, at the range, we were zeroing a couple of rifles; I was starting to shoot a BAR cal 7 RM (not mine), and he handed me a box of 7x64. I put a round directly in the chamber, I closed the bolt and pulled the trigger. I will never understand why, but the rifle shot; I felt a big blow of gas on my face, neck and arms. The (steel) receiver opened up in the lower part for about 1.5 cm. letting fall the trigger assembly, but I wasn't injured and the rifle had no real damage. We only had to clean it deeply and carefully clamp the receiver in a vise to the original width. That event taught me that one can never be too much careful.

uh, that doesnt sound safe.

04 September 2007, 23:18

mete

Crucible says their 416 barrel steel is good to - 40 F !!

05 September 2007, 06:40

Robgunbuilder

I have to say that the secondary explosion effect really has me bothered. I wonder if this is documented fact or lore. I have been told that with the wrong slow burning powder that a primer fired in a 100% density loading could push the bullet well into the rifling followed by delayed powder ignition. The bullet then acts as a barrel obstruction and Kaboom. Hoop strength exceeded.
Is this theory or fact? I do know that failure to ignite has happened with the 600 and 700NE and fed 215 primers. When that happened where was the bullet? It might be worthwhile to load a .600NE with corn meal to 100% density and firing a primer to see how much of an obstruction could in fact be created. Perhaps we should stay as far away as possible from very slow burning powders.-Rob

05 September 2007, 08:25

Macifej

quote:
I'm not a mechanical engineer so my analysis may be flawed,however, I believe that when we are discussing a barrels resistance to pressure based deformation( gaseous vs a fluid in the case of firearms., that this is best decribed as Hoop Strength. Clearly the thickness of the barrel, its materials of construction(alloy) and temp effect the Hoop strength and that strength varies by the alloy, contour, length and thickness of the barrel at any
given point. Obstructions can clearly cause the hoop strength to be exceeded and We probably need to be extremely cautious of the use of thin walled barrels with high pressure loads. Real Big Bore guys pay attention here as your trading off hoop strength vs weight reduction often when trying to build a gun you can carry. Would a carbon fibre wrapped barrel solve this problem? Powders with
burning characteristics resulting in high rapid peak pressures should also be avoided. So what are we to do? I for one have always been in favor of firing PROOF Loads in any new big bore. I proofed the .600OK on a CZ550 with loads calculated to reach 85 KPSI and fired two through the gun, then took it apart and checked all the original measurements before I ever shoulder fired it. I'm still thinking thats a darn good idea.-Rob

All true! Hoop strength is a function of material strength and material section. Pretty tough to get a real number when you're working with a very old action/barrel or a new rig with unknown specification due to standard deviations in material type and condition. (quality control). I'd also be wary of generic steels and investment castings when approaching the upper limits of case strength. Another VARIABLE is material fatigue due to load cycling or condition degradation. You can put 100,000 rounds through most modern combat pistols with little chance of component failure. Doubt one could approach that number with a new Magnum Mauser M98.

05 September 2007, 08:47

Robgunbuilder

From all this data it would appear that excessive headspace coupled with a barrel obstruction of any source, or of course, extremely high pressures due to handloading errors is a real recipe for disaster as are thin walled barrels of questionable steel alloys. I always set the headspace on my guns to just close with some feel on the go guage and/or on the cases I intend to use in the gun. I never accept a loose headspace condition. Low temps with certain Stainless steels may also be a factor. Some Actions seem to come apart easier than others when the case head goes. Some actions fare better than others. Interestingly the lowly Arisaka continues to do surprisingly well despite the fact no one uses them for Big Bores.Generally, The locking lugs may get set back( Many Mausers are prone to this ) but the front of the action takes the brunt of the blast and can fail( M700,M70 etc). This would argue that belted cases with their thicker brass at the most critical points should afford some small additional margin of safety, particularily from a momentary or partial seconday explosion. The entire belt is always enclosed by steel in every modern action I can think of. I also feel that 120% of max pressure proof loads should also always be fired in newly built big bores before ever shoulder firing. There are still too many unknowns and too easy to become a statistic. More to come.-Rob

05 September 2007, 22:35

surestrike

I saw a guy just about blow his left hand off one time with a Weatherby Mark V in .270 Weatherby.

He loaded a .270 win shell into it and let fly. The floor plate and some stock material blew out of the bottom of the gun and gave him some pretty severe lacerations in the wrist and some blow back into the face.

But I should't think we should blame Weatherby for that one. In fact Johnny Walker had some culpability in this severe act of stupidity!

07 September 2007, 05:56

Robgunbuilder

Interesting that a .270 win would fire in a .270 WBY chamber. Firing a non belted case in a belted chamber has just got to be a real bad news recipe. Nevertheless, once the case ruptures the action may or may not be able to contain it.-Rob

07 September 2007, 07:54

Idaho Sharpshooter

RGB,

interesting hypothesis. Back in 1978-79 a gentleman named Caldwell (you would have liked him RGB, he had both eight bore and four bore DR's both by H&H. He even let me shoot them in the Speer test lab in the basement. You haven't lived until you have accidentally "doubled" an eight bore, even with BP loads!!) tried to replicate the SEE phenomenon. Their only success was with about a 50% loading density of 4831 in a 25-06 with a heavy bullet. Their findings pointed at a low density charge that caused the primer flame to "...dance across the horizontal powder column, igniting ONLY the surface portion...causing a back lash-type of secondary ignition of the other half of the charge...the bullet had moved forward into the chamber leade area and stopped...then got hit with the SEE of the other half of the powder charge as it ignited". They suspected that the initial flame racing across the top of the powder column may have somehow "scorched" the outside of the sticks of 4831 and burned off some of the deterrent coating. That would change the burn rate considerably, and that would cause a tremendous pressure spike at the base of the bullet. Made sense to me.

Any here with a chemical background to add to this?

Rich
DRSS