How and why Guns explode.
 

Many years ago I bought a Luger outside a bar on the wrong side of town from a down on his luck gentleman. Cost - $20.00

I remembering thinking "will this gun explode" when I fire it.
I took it home and thoroughly cleaned and checked the gun out.
I removed a lot of rust and pitting, checked for cracks along the rail (the good old tuning fork check) and replaced the take-down lever spring and the hold-open latch (the gun didn't have one).
I checked the barrel as much as I could ... it had a bright shiny bore with excellent lands and grooves ... I was kinda surprised by this but pleased.
The barrel was a replacement and had a target style sight ... I think it had once been someones proud little shooter project.
The gun is a marriage of 2 Guns ... the frame is DWM (3003-h) & the receiver is a 1938 Mauser (6879) with the trigger bar being the only other mismatch (91)

Still I have to tell you that I was very nervous the 1st time I fired it.

But it was phenomenal ... tight groupings with zero feed or misfire problems ... I had the foresight to use a new MecGar mag. :p

I don't have any 'before' pictures (mores the pity) but here she is after I cleaned her up... million dollar chip and all.
Long since gone but still in my memory. http://i.imgur.com/NXpGI.gif

https://i.imgur.com/ekfJ3Yv.jpg

The point of this post is someone was NOT so lucky ... Scott @ Kentucky Ballistics ... and so i present this sobering video followed by an excellent educational and informative video by Ian McCallum @ Forgotten Weapons.

My 50 Cal Exploded ... By Kentucky Ballistics
https://www.youtube.com/watch?v=1449kJKxlMQ

Earth-Shattering ka-Boom! How (and Why) Guns Explode ... By Ian McCallum and Forgotten Weapons
https://www.youtube.com/watch?v=71OGayW7CnI

The 50 cal. ammunition was a very old and now obsolete military round. He explains in the video that it was very likely over charged. There were no obstructions in the barrel of the gun, and it fed normally prior to the catastrophic failure.

In the USA, we have a standards organization called SAAMI which publishes specifications for ammunition and firearm chambers. This includes testing of commercial ammunition to pressure standards. When a manufacturer makes a new firearm, one of the last things done prior to shipment is to "proof" the firearm using an overpressure round. This is done commercially in the United States.

In Europe, there is a similar organization called CIP. They publish similar standards for ammunition and firearms. In Europe, the majority of proof testing of firearms is done by governments. This is why Lugers have the various proof marks from government proof houses, and firearms made for export may have proof marks done by the manufacturer.

SAAMI and CIP coordinate their work.

In Europe, ammunition is also marked by proof houses, as approved through a relationship with CIP Type Approval.

Note that when our WW-I and WW-II era firearms were made, these standards organizations didn't exist, and much of the proof standards were established by manufacturers and government agencies in each individual nation working together. The same goes for the ammunition of that era. And don't forget that much of the ammunition made prior to the 1940's (and 1980's in the Eastern Block nations) used corrosive primers.

Each of the standards organizations publishes standards as free to download PDF documents.

https://bobp.cip-bobp.org/en/tdcc_public


https://saami.org/technical-informat...ami-standards/


The CIP site has a great group of videos on the procedures involved in firearm proofing.

If you ever decide to become a reloader, you need to become familiar with these dimensional and pressure standards. Note that too much powder charge in a cartridge is not the only potential cause of overpressure. This can happen easily with under charged cartridges because the bullet can have difficulty smoothly entering the leade of the barrel and engaging it's bullet's ogive in the barrel's rifling. In fact, most cartridges have multiple pressure peaks as the are discharged, travel into and through the barrel.

This isn't mentioned as a potential cause of the catastrophic failure you witnessed, but it's a distinct possibility for aging ammunition that has sustained internal damage to the powder charge. Since he was using aged military factory rounds, and he didn't know the storage conditions over the years it was stored, I suspect that this may also have been the cause of the failure.

The Exact Moment
 

I have isolated the frame where Scott's 50 Cal. gun explodes.
Re-loaders take note ... hot rounds are dangerous.

https://i.imgur.com/MX08Vxl.png

A "Don't try this at home," moment.
A fool with luck on his side-that time.

Imho, that rifle is a poor design. There was no way for it to fail "safely".
Granted that it's possible that no .50 cal rifle could have survived that round.
His earlier shot going wide makes me think the sabot disintegrating in the barrel may have caused an obstruction.
I would be curious to see a closer look at the barrel and to see if it was a failure of the sabot or powder degradation or a combination of both that caused the detonation.

Ian McCollum did a video a while back about the crappy 8mm Turkish ammo that was going around a few years back showing how
this ammo had gotten hotter with age.
https://www.youtube.com/watch?v=AunvMjcJPHY

I bought some of that ammo back about 10 years ago and I can confirm his findings.
About half the ammo was duds and the rounds that did fire were noticeably hotter than what I was used to.

Totally agree Dana ... when he 'screwed' the end cap on it reminded me of a 'pipe bomb' which is essentially what the gun turned out being.

If you want to play with a 50, and I do play with a 50, you don't want the cheapest gun. I doubt that a McMillan or an Armalite would have failed in such a spectacular fashion.

On another forum, the consensus seems to be these were NOT military surplus SLAP rounds but aftermarket reloads using SLAP like components. This ammo sells for really big bucks so fakery is common (Should not surprise this forum) Several failure modes are possible. I do not have an opinion on the design of the breach. But if I was to want a 50 Browning, I would want to see some really big locking lugs somewhere and maybe a pressure relief path

I watched Scott's video and then Ian's. Very sobering indeed. I have a Inglis 1943 BOYS rifle rebarreled to .50 BMG postwar. I used to shoot old 1950's ball ammo I got cheap, but these rounds had been around and probably not kept under the best conditions. Some of these rounds fail to fire, but I never got any hot loads out of them as best I know. Still have a few of those rounds. I have some old 1970's (I think), Brazilian AP that never gave me any problems. After seeing this, I don't think I will be putting anything but my factory fresh PMC and Federal ball through the boys. I don't want to risk what Scott went through and my BOYS is a nice collectible piece of history which can't be easily replaced. I now appreciate more than ever the BOYS design, specifically the offset of the sights to the left of center. In the event of a catastrophic failure only your shoulder is directly in line with the bolt and the shoulder is shielded by the shoulder piece. Also, I feel much better about the BOYS two locking lugs at the front of the bolt and the third lug bolt handle, than just having a screw on cap like Scott's rifle. I know the threads are engineered to handle great pressure, but bolt lugs put a lot more steel against steel I think. A couple pics to show what I mean. I will start another thread to share more pics of the BOYS rifle.

Mark Serbu comments on Scotts accident with the Serbu RN-50

markserbu
"Just a brief explanation of the RN-50 blow-up accident that occurred to Scott from Kentucky Ballistics. I will be coming out with a detailed analysis video shortly after I get my hands on Scott's rifle and some of the ammunition he used."

RN-50 Blow-Up https://www.youtube.com/watch?v=5AY6iEVhJE8

And Rex analyses what he thinks went wrong ... which I agree with and rolandtg (Dana) already commented on ... good call Dana.
Why His 50 BMG Exploded ~ Rex Reviews https://www.youtube.com/watch?v=ardw09S7GfE

Stay Tuned

Locking lug sheared an ear, jammed in track-apparently.
Bring back pistol I had a long time.
A CYQ.
No animals or small children injured.

WOW Mike ... both impressive and troubling @ the same time.
Pistol flaw, hot ammo or both ???
I was never a P.38 fan ... Glad you were OK Mike. :thumbup:

My former wife worked at Ithacagun in the early 70s while I attended Ithaca College. I'd drop her off each morning, go up the hill to classes or to my part-time job, and pick her up at the end of the day. If I arrived earlier than her quitting time, I'd hang out in the service dept's waiting area, which afforded eavesdropping on company scuttlebutt, and sometimes let me witness the arrival of customers -- sometimes they were irate.

A common malady was burst barrels. It was policy to have all such guns independently tested to establish the cause and assign liability for the failure. Burst barrels were invariably found to have had obstructions. It doesn't take as much as one might think to catastrophically obstruct a barrel, so if a bit of a sabot remained...

:( Yet another incident today. This appeared for sale on a gun board I peruse.
======================
S&W Mosel 629 Blown Up

Hot load blew the cylinder and wrecked the frame / the rest of the gun could be used for parts or kept together as a conversation piece , $400 obo

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With the ammo shortage going on I think there is a lot of shady ammo floating around out there ... be careful guys please. :(

mrerick, Good observations and sound advice in your post.
I do think it's important to note the differences between the purpose of the two organisations, the CIP and the SAAMI.
The CIP began in 1914 as the standardisation of the old European proof houses, some of which date back to the 17th century. It now regulates a common set of standards and tests which are mandatory for all guns and samples of all batches of ammunition, before they can be sold in the 14 member countries. Firearms and ammunition which have passed test must be so marked, for the benefit of the consumer.
The SAAMI is a post WW2 industry group that has developed a set of standards for the firearms industry. While these standards may be technically comparable to the CIP, they are not mandatory. A gun or ammo maker can chose to follow the SAAMI standards, or not. Manufacturers are not obliged to inform consumers if their product complies with the SAAMI standard by way of markings or any other method.
I agree that in this case, the ammo would be the obvious culprit. But we have no way of knowing how the rifle was proof tested.
Mark

I guess that is now a '3 shooter'

I watch "Demolition Ranch" on you tube. He has had many shows with obstructed barrels..Surprising how many are NOT affected.

Serbu,s take on the explosion
 

Vitaly, Thanks! A short & sweet video for those of us who have been following this.

No problem, Greg.
I have been a big fan of Serbu. Like his channel, learned a lot in homemade gun building.

I believe he has a strong background[?degree?] in engineering.

I hate to see not always deserved very emotionally charged blames vs credits without first investigating the issue, facts.

It's interesting that we are careful with Luger's ammo god forbid not to brake some parts in it.
No-no for hot ammo.

Imagine would would happen to it with the several fold charge...

I believe, any gun even with the best design has a breaking point and can explode...