Blown up 50 Cal.

This was a factory produced rifle... with a reliable reputation. The round that blew the rifle up and the preceding rounds of the same manufacturer were old military ammo. ..50 caliber SLAP ammunition was developed by the Marine Corps during the mid/late 1980s and was approved for service use in 1990 during Operation Desert Storm. It uses a reduced calibre, heavy metal (tungsten) .30 inch diameter penetrator wrapped in a "plastic" sabot or "shoe" of .50 inch diameter. They developed similar ammo for the .308 rifles. They experienced sabot problems with the ,308 ammo. Possibly with age there was a plastic problem and an obstruction immediately ahead of the chamber caused this catastrophic failure. Normal chamber pressures for a .50 BMG are 55,000 psi... it is estimated to shear the threads of the action the pressure was about 85,000 psi.

This shows that eye protection is important too...

This guy is so lucky to be alive... he thinks god had something to do with that (roll eyes) ... it’s a good video until god pops up...
 
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Theres another thread already on this here: https://www.canadiangunnutz.com/forum/showthread.php/2153368-Kentucky-Ballistics-KABOOM

A lot of people are blasting the gun design. I would think that if the design was an issue you'd have more incidents like this though.

This was a factory produced rifle... with a reliable reputation. The round that blew the rifle up and the preceding rounds of the same manufacturer were old military ammo. ..50 caliber SLAP ammunition was developed by the Marine Corps during the mid/late 1980s and was approved for service use in 1990 during Operation Desert Storm. It uses a reduced calibre, heavy metal (tungsten) .30 inch diameter penetrator wrapped in a "plastic" sabot or "shoe" of .50 inch diameter. They developed similar ammo for the .308 rifles. They experienced sabot problems with the ,308 ammo. Possibly with age there was a plastic problem and an obstruction immediately ahead of the chamber caused this catastrophic failure. Normal chamber pressures for a .50 BMG are 55,000 psi... it is estimated to shear the threads of the action the pressure was about 85,000 psi.

This shows that eye protection is important too...

This guy is so lucky to be alive... he thinks god had something to do with that (roll eyes) ... it’s a good video until god pops up...

Gatehouse posts about the development of these rounds in the other thread. It mentions that the 30cal ones had an issue with catastrophic barrel failures - the round was losing the sabot and the penetrator was coming out the side of the barrel! Quite different from what happened here IMO.
 
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Why do you put your faith in the gun based purely on not finding other catastrophic failures? Some things to consider

-Mark owns and runs the company pretty much himself. Any warranty issues could easily be hidden
-There aren't a lot of Serbu guns out there, let alone RN-50s
-Literally no other manufacturer has ever put out a gun like it.
-Serbu's Canadian BFG-50A guns nearly all had issues. He blames our ammo, which is the exact same stuff Americans would be shooting...

Once again I believe it's the ammo but look at what the gun did when it failed. It's a #### design with absolutely no safety features to accommodate a failure. I think only Vulcan gunworks has put out a less safe .50...
 
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Why do you put your faith in the gun based purely on not finding other catastrophic failures? Some things to consider

-Mark owns and runs the company pretty much himself. Any warranty issues could easily be hidden
-There aren't a lot of Serbu guns out there, let alone RN-50s
-Literally no other manufacturer has ever put out a gun like it.
-Serbu's Canadian BFG-50A guns nearly all had issues. He blames our ammo, which is the exact same stuff Americans would be shooting...

Once again I believe it's the ammo but look at what the gun did when it failed. It's a #### design with absolutely no safety features to accommodate a failure. I think only Vulcan gunworks has put out a less safe .50...

Funny you mention Vulcan gunworks, I can find plenty of people complaining about their guns online while trying to find more examples of major issues with the Serbu. The only thing I have found about the Serbu is extraction issues with some kinds of ammo, and they even state on their website that certain ammo doesn't play nice with their gun.

What sort of issues did the BFG-50A have? Were they blowing up?
 
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Funny you mention Vulcan gunworks, I can find plenty of people complaining about their guns online while trying to find more examples of major issues with the Serbu. The only thing I have found about the Serbu is extraction issues with some kinds of ammo, and they even state on their website that certain ammo doesn't play nice with their gun.

What sort of issues did the BFG-50A have? Were they blowing up?

They were advertised as semi-automatic but many guys only had luck running them as straight pulls most of the time. Serbu blamed the ammo, American Eagle, PMC etc. The same stuff they shoot in the US. Just trying to illustrate that Serbu is hardly a top tier manufacturer putting out top shelf product. Quite the opposite in my opinion, one I have formed slowly over the years from my own and others' experiences.
 
This was a factory produced rifle... with a reliable reputation. The round that blew the rifle up and the preceding rounds of the same manufacturer were old military ammo. ..50 caliber SLAP ammunition was developed by the Marine Corps during the mid/late 1980s and was approved for service use in 1990 during Operation Desert Storm. It uses a reduced calibre, heavy metal (tungsten) .30 inch diameter penetrator wrapped in a "plastic" sabot or "shoe" of .50 inch diameter. They developed similar ammo for the .308 rifles. They experienced sabot problems with the ,308 ammo. Possibly with age there was a plastic problem and an obstruction immediately ahead of the chamber caused this catastrophic failure. Normal chamber pressures for a .50 BMG are 55,000 psi... it is estimated to shear the threads of the action the pressure was about 85,000 psi.

This shows that eye protection is important too...

This guy is so lucky to be alive... he thinks god had something to do with that (roll eyes) ... it’s a good video until god pops up...

Is 85k psi really all it would take to shear that threaded cap off? I expected it would take much more.
 
Is 85k psi really all it would take to shear that threaded cap off? I expected it would take much more.

According to word of mouth from the manufacturer after hearing that this failure happened and severely injured the operator in the USA. I wouldn't put a lot of trust in that number.
 
They were advertised as semi-automatic but many guys only had luck running them as straight pulls most of the time. Serbu blamed the ammo, American Eagle, PMC etc. The same stuff they shoot in the US. Just trying to illustrate that Serbu is hardly a top tier manufacturer putting out top shelf product. Quite the opposite in my opinion, one I have formed slowly over the years from my own and others' experiences.

I don't know about other BGF-50A, but mine has never had extraction issue and I have shot everything through it, even my own reloads, it has never missed a beat
 
According to word of mouth from the manufacturer after hearing that this failure happened and severely injured the operator in the USA. I wouldn't put a lot of trust in that number.

85k psi seems pretty low. That doesn’t leave much room for safety. Wouldn’t a well made action survive way more pressure than that?
I figured 85k psi would probably destroy a brass case and cause the bolt to stick shut. All the gasses/debris should get blown out the relief port. I didn’t think that was catastrophic failure territory
 
Scary Situation Indeed, We kinda take for granted how much pressure is actually generated from full power rifle cartridges. Some quick engineering calculations based on a photo of the breech of that model does indeed show that the shear failure would occur around 89000psi assuming a good quality steel like 4140. Using a 50 BMG case head as reference, the outer thread of the the breeck would be a 1.75" - 5 thread pitch, giving a major diameter of the breech at 1.74" (External Thread and the cap at 1.75" (Internal Thread) or so. Using that info in a thread shear equation (π*(Thread Pitch)*(Engagemrnt Length)*(D[SUB]E[/SUB])*((1/(2*(thread Pitch)))+0.57735*(D[SUB]E[/SUB]-D[SUB]I[/SUB])) *for the nerdy types*. Then taking the yield strength of 4140 at 95000psi, in shear most steels yield at 55-60% of this strength, so 55100pis here, we get a thread blow out at 89 967 Psi. which is still a heck of a lot of pressure. Considering SAAMI spec proof loads for 50 BMG is 65000psi, we're talking a design safety factor of 1.38, which is fairly resonable. Just goes to show what we sometimes take for granted on everyday objects.
 
Are you considering the actual back thrust generated? PSI pressures are all very well, but the back thrust actually applied to the breechface isn't quite the same thing.
 
That was a real close call with death. Not to belittle the trauma in any way but the jugular veins do not carry oxygenated blood to the brain as he had stated. Rather they drain the brain. Without plugging the hole he would have bled out very quickly. The risk of stroke would have been from a clot in the damaged lung making its way to the heart and then sent to the brain. 5 units of blood is a massive transfusion equal to about 30 - 40 % of the total blood volume in a guy that size.
 
Scary Situation Indeed, We kinda take for granted how much pressure is actually generated from full power rifle cartridges. Some quick engineering calculations based on a photo of the breech of that model does indeed show that the shear failure would occur around 89000psi assuming a good quality steel like 4140. Using a 50 BMG case head as reference, the outer thread of the the breeck would be a 1.75" - 5 thread pitch, giving a major diameter of the breech at 1.74" (External Thread and the cap at 1.75" (Internal Thread) or so. Using that info in a thread shear equation (π*(Thread Pitch)*(Engagemrnt Length)*(D[SUB]E[/SUB])*((1/(2*(thread Pitch)))+0.57735*(D[SUB]E[/SUB]-D[SUB]I[/SUB])) *for the nerdy types*. Then taking the yield strength of 4140 at 95000psi, in shear most steels yield at 55-60% of this strength, so 55100pis here, we get a thread blow out at 89 967 Psi. which is still a heck of a lot of pressure. Considering SAAMI spec proof loads for 50 BMG is 65000psi, we're talking a design safety factor of 1.38, which is fairly resonable. Just goes to show what we sometimes take for granted on everyday objects.

And then you've got the two ears on the lower that got blown off too. No idea how much force they can withstand, but it's got to factor in somehow.
 
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