Well that didn't go as planned - Kentucky Ballistics went Kaboom!

[saxon]

First off, I have not analyzed the gun design in this video nor do I have any professional association with Serbu Firearms. I admit to knowing Mark Serbu and we have discussed engineering/design on various gun projects (not this gun though) in the past.



1. Almost all guns have threads at the highest pressure containing area, they are called barrel threads and they are usually between the barrel and the receiver or barrel extension. So when you say you would never shoot a gun with threads holding the pressure you are ......
2.Proof pressure for a 50 bmg is 65000 psi (had to look this up on the internet since SAAMI does not list 50 bmg so it might be suspect), it is not 2x normal pressure.
3. SLAP ammo has a bullet weight about 1/2 of the normal ball 50 bmg. The powder charge is very different that the normal load since it has to cycle a M2 HB with half the mass going down range. They had many problems designing the SABOT for the SLAP rounds and finding a suitable material for the SABOTs. The rounds that are on the surplus market are very questionable to start with and given the unknown storage, the material properties of the SABOT and powder should be suspect. They were never meant to be shout out of a Barret or any gun with a muzzle brake.
4. Many guns have a safety factor less than 2. Yes this surprised the sh*t out of me since many other engineering industries (not including aerospace) prefer closer to 4 safety factors.
5. "Other guns have multiple safety features if the lugs fail" This is not true for many designs, specially since shot firearms. Rolling block, sliding breach, break open actions all typically have no method of containment other than the primary pressure containing component.
6. Weight of a gun is the sign of a safe design, well the M2HB weights over 83lbs without tripod and there have been people gutted by them when they let lose. Design, not weight is the only quantitative measure of safety.



just saying

 

[Red98422]

First off, I have not analyzed the gun design in this video nor do I have any professional association with Serbu Firearms. I admit to knowing Mark Serbu and we have discussed engineering/design on various gun projects (not this gun though) in the past.



1. Almost all guns have threads at the highest pressure containing area, they are called barrel threads and they are usually between the barrel and the receiver or barrel extension. So when you say you would never shoot a gun with threads holding the pressure you are ......
2.Proof pressure for a 50 bmg is 65000 psi (had to look this up on the internet since SAAMI does not list 50 bmg so it might be suspect), it is not 2x normal pressure.
3. SLAP ammo has a bullet weight about 1/2 of the normal ball 50 bmg. The powder charge is very different that the normal load since it has to cycle a M2 HB with half the mass going down range. They had many problems designing the SABOT for the SLAP rounds and finding a suitable material for the SABOTs. The rounds that are on the surplus market are very questionable to start with and given the unknown storage, the material properties of the SABOT and powder should be suspect. They were never meant to be shout out of a Barret or any gun with a muzzle brake.
4. Many guns have a safety factor less than 2. Yes this surprised the sh*t out of me since many other engineering industries (not including aerospace) prefer closer to 4 safety factors.
5. "Other guns have multiple safety features if the lugs fail" This is not true for many designs, specially since shot firearms. Rolling block, sliding breach, break open actions all typically have no method of containment other than the primary pressure containing component.
6. Weight of a gun is the sign of a safe design, well the M2HB weights over 83lbs without tripod and there have been people gutted by them when they let lose. Design, not weight is the only quantitative measure of safety.



just saying

Ok....I can't be the only one freaked out just a bit by that nugget of firearm safety factor!!!! Jeez as someone who does heavy equipment and crane operations I couldn't begin to imagine using rigging rates only 2 overload

 

[Boboclown]

I think in one of his previous vids where he was shooting SLAP I commented (IIRC) that it wasn't a good idea to shoot SLAP in a rifle with a muzzle brake. That doesn't seem to be the reason for this kaboom though.

Its meant for M2s and tanks, its hot ammo that is also longer IICR. On top of not knowing how it was stored and condition of ammo, and it being not too consistent, its never a good idea to shoot it. The ammo that never made it through also got dumped and ended up in civilian market as well. Never ever a good idea to shoot it.

I don't think the folks who used it in the M2 even liked it.

 

[CountryGent]

Yikes! Fellow is very lucky to still be among the living.

 

[Xaevian]

Well, at $100/round, there is plenty incentive to suffer from "but made in China" syndrome.

My theory would be non-OEM parts.

 

[The Heretic]

Well, at $100/round, there is plenty incentive to suffer from "but made in China" syndrome.

My theory would be non-OEM parts.

Yeah, the sabot rounds are expensive. I sold mine for $25 per round, but that was 15-20 years ago. I think I might still have one laying around somewhere. Like I said, I have seen home-rolled copies but they are obviously not Winchester made SLAP.

 

[saxon]

 

[waltermitty]

Mark Serbu....

 

[Red98422]

Mark Serbu....

Some of the people in that comments section are perfect examples of gun owners eating themselves.

I don't even know how many times I read "I bet a Barret wouldn't have done that" or "this gun needs to be recalled immediately" blah blah blah.

the reality of the matter as I'm sure most here are aware, is that we are all responsible for using firearms within their limitations and once you exceed those limits you're on you own.

thankfully it seems that both Scott and Mark are treating this incident like adults.

 

[ilikegunspdx]

This guy had some old, old SLAP rounds and had one that was loaded a bit too hot and destroyed his rifle. Anyway, he survived, but not by much. Good video and he goes into quite a bit of detail. Worth watching from start to finish. It also parallels with why you wouldn't want to shoot reloads that you don't know the direct history of.

Was it loaded a bit too hot or did it become "hot" over time I wonder? Ian at forgotten weapons did a good follow up of this video last week or whatever after it happened and discussed how some powders can become more hot as they age.

I agree about shooting reloads that u didn't reload urself. How many kabooms have we seen associated with reloads (tons!)? Only recently with the ammo shortage have I seen more kabooms with "manufactured" ammo. And those were mostly by off brands not standard brands.

 

[RVTECH]

Was it loaded a bit too hot or did it become "hot" over time I wonder? Ian at forgotten weapons did a good follow up of this video last week or whatever after it happened and discussed how some powders can become more hot as they age.

I watched the video carefully this morning and truthfully Ian did NOT actually 'discuss' how some powders can become more 'hot' as they age. In fact his only reference to this was at about 3:45 when he said ,
'some will deteriorate in ways that make them higher pressure over time'

What he did discuss, and quite well, were the most common causes of failures such as bore obstructions of which he gave many examples, and mechanical aspects of firearms and how they have been modified and improved for safety in the even of an overload, case failure or other issues such as in battery or out of battery detonation.

The takeaway I got from this was when he mentioned the threaded cap on the Serbu. He said specifically the 'threading on the end cap sheared off' and after watching the rest of the vid and how he described the various ways manufactures have designed 'fail safe' systems to keep the parts of the action from blowing back into the shooters face.

So while he described and showed many rifles with there added safety designs such as extra locking lugs, flame shields and deflectors. It appears the Serbu has nothing designed to prevent this in the event of this - such as if the threads fail.

Bottom line is the threads were the only thing keeping the cap secured with nothing to prevent it from flying back in the event of thread failure.

 

[The Heretic]

So while he described and showed many rifles with there added safety designs such as extra locking lugs, flame shields and deflectors. Tt appears the Serbu has nothing designed to prevent this in the event of this - such as if the threads fail.

Bottom line is the threads were the only thing keeping the cap secured with nothing to prevent it from flying back in the event of thread failure.

There are lugs behind the cap - they sheared off too.

 

[RVTECH]

There are lugs behind the cap - they sheared off too.

Got it! I was unaware of this and looked at a picture of one to see how it operated.

 

[Dinglenutz]

When I was shopping for a 50, I looked at the Serbu, and decided it didn't look like something I wanted to trust. I'm not a firearms designer and it might be fine, but the thing I think I heard, that the manufacturer figured that the chamber pressure ran up to 80k PSIC, and that caused failure, isn't confidence inspiring.

I expect more engineering margin from modern firearms, personally.

I went with the Noreen ULR 50 because it's dead simple and seems to have the potential for both extreme robustness and accuracy. There are many others out there, including the Barrett 99, that would also work. My brother had a 99, and it seemed sturdy but I was hopeful that the TImney trigger that comes standard on the Noreen would be better. The ULR also has a barrel that's quite long and stupidly heavy.

 

[Member 34319]

There are lugs behind the cap - they sheared off too.

From my understanding, those lungs are only there to prevent someone from closing the action on a round with the cap not threaded all the way in. Sort of like a headspace insurance device. I don't believe those lugs help in anyway to hold the cap in place.

I read here some are defending the gun as if it is in the crosshairs.

When this rifle first came out, back when Nutnfancy was still on YouTube, the cap was my first red flag. I'm not saying I knew this was going to happen, I'm saying, I would never see this as an option to get into 50bmg.

Now that this video exists. I would NEVER buy one nor shot one. Sure, a kaboom will likely never happen, BUT IF IT DOES, there is no denying that this design is definitely inferior to others.

There is a lot of aging surplus 50 out there. My brief stint at TNW, I saw pallets of 50bmg projectiles and powder sitting in rot in Mr Bero's various buildings. I can only imagine Tim will eventually sell off all that stuff and someone will make ammo with it. Scary stuff! I want to say Tim did make ammo with his random components at one time and folks that bought it had all sorts of issues!

Moral of this story, playing with 50bmg, maybe don't be cheap?!? That $1 a round surplus tin of ammo could be hazardous to ones health. SLAP out maybe even Raufus rounds from some random guy at a gun show for 1/2 usually cost!?!?

 

[tac]

OK, right thread this time...

 

[The Heretic]

Moral of this story, playing with 50bmg, maybe don't be cheap?!? That $1 a round surplus tin of ammo could be hazardous to ones health. SLAP out maybe even Raufus rounds from some random guy at a gun show for 1/2 usually cost!?!?

SLAP ammo is not cheap. I paid about $15 per round for it 20 years or so ago, today it is about $100 per round if you can find it. I sold mine about 15 years ago for $25 per round because I had read this:

.50 BMG saboted rounds (Gale McMillan)

Gale McMillian knew his stuff - besides his stocks & rifles - he was often involved in testing new guns and ammo, including .50 BMG for the military.

 

[Member 34319]

SLAP ammo is not cheap. I paid about $15 per round for it 20 years or so ago, today it is about $100 per round if you can find it. I sold mine about 15 years ago for $25 per round because I had read this:

.50 BMG saboted rounds (Gale McMillan)

Gale McMillian knew his stuff - besides his stocks & rifles - he was often involved in testing new guns and ammo, including .50 BMG for the military.

I know. My point was, if a person who owns a 50 sees a bunch of slap or raufus rounds for less than normal prices, one should be curious to why. They should also be extremely cautious when shooting that ammo. This is not the 1st time I've seen old questionable 50 not work correctly.

 

[Hueco]

OK, right thread this time...

That sure does make me wonder about Mr. Serbu's liability in all of this. If Average Joe were shooting ammo not designed for the rifle...seems Average Joe would be on the hook for the boom.

But, since Serbu sent out a beefy barrel for specific use with these SLAP's ... I wouldn't want to be in his shoes right now. Regardless of whether or not the Mr. Kentucky Ballistics refuses to sue Serbu...if KB used a health insurance, his insurance company may go after Serbu.

Yea...wouldn't want to be him right now.

 

[ilikegunspdx]

That sure does make me wonder about Mr. Serbu's liability in all of this. If Average Joe were shooting ammo not designed for the rifle...seems Average Joe would be on the hook for the boom.

But, since Serbu sent out a beefy barrel for specific use with these SLAP's ... I wouldn't want to be in his shoes right now. Regardless of whether or not the Mr. Kentucky Ballistics refuses to sue Serbu...if KB used a health insurance, his insurance company may go after Serbu.

Yea...wouldn't want to be him right now.

I think there are 2 issues, 1 being pressure, and the second being chamber size.

As Ian explained it, the pressure was thought to be 80k psi to do that damage (I believe that info was from serbu guy). So I think the Serbu guy would claim that pressure was too high.

But I get what u r saying, serbu guy said SLAP would not be safe in other barrels due to chamber size, then serbu guy sent him a barrel with bigger chamber size to work for the SLAP round. So it makes u wonder if chamber size plays a role.

So the real question is what actually caused the barrel obstruction, pressure, or an issue with the chamber? I don't know a darn thing about it, just trying to clarify what I heard on the videos.