More on Kentucky Ballistics - Serbu

[mgmorden]

I am confused. As I understand it:
KB blew up the first Serbu with spooky SLAP ammo, and repeated the exercise out of of that box after he healed up.

Now he says "the exact same load" at 190000 psi blows up a Barrett.
Where did that load come from? What connection with the first incident? Did he still have some of the defective/sabotaged ammo?
If so, why has it not been dissected and inspected instead of making loud videos?

Is it intentionally fresh loaded with a fast burning powder to generate triple pressures? Did he blow up a third Serbu with such a concoction?

A lot of people "don't watch the videos" and draw conclusions. Here is the video where he blows up the 2nd RN50:



He shoots all of the rest of the slap rounds he had from the original batch and determined that they were definitely overpressure/hot but couldn't get the gun to blow up. THEN starting at the 22:25 mark he explains that he has loaded a round to mimic the pressures that it should have taken to blow up the action - around 180k PSI. He then proceeds to shoot THAT round to blow up the second RN-50. That's also the load that he used to blow up the Barret.

It's important if you're going to throw information around on this to actually watch the videos and pay close attention to what is being said as the details on such things are important. I'm sure everyone has played the telephone game before and noticed how fast little things change as they're repeated.

 

[Jim Watson]

Well sure enough, I did not retain that from the mumbletube account.
He indeed blew up two guns with intentional calculated gross overloads, not the initial spooky SLAP.

Considering the mess it made out of the Barrett, I now wonder about all those posts about the inferiority of the Serbu because a "good gun" would not be demolished so dangerously.

The obvious next step is to gradually increase pressure until a "good gun" is damaged beyond use and see what it does to a Serbu.
This would be somewhere short of an uncontainable triple load. Double?

 

[D.B. Cooper]

Considering the mess it made out of the Barrett, I now wonder about all those posts about the inferiority of the Serbu because a "good gun" would not be demolished so dangerously.

Not so fast. Take a look at the slow motion on that Barrett demolition video. Most of the force went straight downward with not much going rearward, toward the shooter. Granted, I wouldn't want to be around either when it blew up, but one appears to be more survivable.

I also have to call into question his destructive rounds that he used. How can anyone possibly know what was in that SLAP round that blew up the first gun and nearly killed him? Other than deliberately surpassing the failure point of the metal itself, which, if one uses that as the standard, then one is not testing the design, one is testing the metallurgy.

 

[David Hoback]

How much is the Serbu compared to the Barrett? Some of you crack me up with your expectations of things. Once again, YOU are the reason for these things!

 

[rust collector]

Use the proper ammunition in a gun in good condition. If you do not, you assume the risk of injury.

There will always be higher strength steels, better designs, sturdier (if heavier and clumsier) and more expensive options. Every firearm is a compromise. Youtubers make money by getting attention.

 

[Jim Watson]

There are a couple of The Seventy Maxims of Maximally Effective Mercenaries that apply here:

14 "Mad Science" means never stopping to ask "what's the worst thing that could happen?
25 "If a manufacturer's warranty covers the damage you do, you didn't do enough damage."

 

[Kano383]

The test that he didn't do... And that should have been done: simulate a case rupture. First with a standard round, then (IF nothing bad happened), with one of those SLAP, and then (IF nothing bad happened still), with a 150% pressure test-round.

If nothing bad happens with the first round I owe someone a beer. If nothing bad happens with the last one, I owe someone a six pack.

If Ka-Boooom!, that would prove that Serbu's calculations for the breech cap threads' ultimate strength are correct... And that the design is incorrect.

 

[Goosey]

The test that he didn't do... And that should have been done: simulate a case rupture. First with a standard round, then (if nothing bad happened), with one of those SLAP, and then (if nothing bad happened still), with a 150% pressure test-round.

This is a man whose channel is based on shooting giant gummy bears with elephant guns and throwing folding tables across his lawn... any kind of in-depth analysis or useful learning is NOT going to happen on his channel

 

[D.B. Cooper]

This is a man whose channel is based on shooting giant gummy bears with elephant guns and throwing folding tables across his lawn... any kind of in-depth analysis or useful learning is NOT going to happen on his channel

We have a winner!!! No more calls please.

This is another perfect summation. If I were a moderator, I'd close the thread right here. And given that we are now eight pages and 184 posts into this, with no clear consensus on cause or responsibility...well...much like shooters on the grassy knoll, magic bullets, crop circles, and what happened at the Roanoke Colony...we will never know.

 

[Nuclear]

We have a winner!!! No more calls please.

This is another perfect summation. If I were a moderator, I'd close the thread right here. And given that we are now eight pages and 184 posts into this, with no clear consensus on cause or responsibility...well...much like shooters on the grassy knoll, magic bullets, crop circles, and what happened at the Roanoke Colony...we will never know.

I’m not saying it’s aliens, but it’s aliens!

Sorry, couldn’t resist. As someone who in a previous life spent years figuring out how complicated systems could catastrophically fail, and how to manage that risk, Serbu did not bother to do so.

 

[Reeferman]

This is a man whose channel is based on shooting giant gummy bears with elephant guns and throwing folding tables across his lawn... any kind of in-depth analysis or useful learning is NOT going to happen on his channel

And now his shtick is blowing up guns on purpose. I suppose there are some who get off on this but for many it is about as stupid as one can get.

 

[MEHavey]

a man whose channel is based on shooting giant gummy bears with elephant guns

Actually....
I was impressed as to how tough gummy bears are.






(I'm also impressed by how expensive they are....)
https://giantgummybears.com/gummybears.aspx

_BUT_ quite Inexpensive compared to ballistics gel
https://www.clearballistics.com/

 

[P Flados]

The testing with the remaining Bad Slap Ammo (BSA) indicates that the batch had a few with normal pressure, but most were in the range of I would say 130% to 180%. This is just my WAG based on my own experiences and the primer damage and breech cap / case removal difficulties. The Overloaded Test Ammo (OTA) used for the remaining two gun destruction tests was reportedly loaded for a pressure expected to be 345% of normal. The gun damage caused by the original event appeared more severe than the damage caused by the OTA. I would expect that the BSA was loaded with a powder that occupies most of the space in the case (Using Quickload, most optimal commercial powders would be loaded at least to 80% full). A loading error involving "a double charge" is probably not possible. A loading error with the powder charge increased from 80% to 100% fill, only pushed pressure up to 200% of normal. This is an obvious "big error", is unlikely to occur unnoticed and does not approach the pressure indicated for the original event. A loading error using a single "wrong powder" would not explain the high variability observed when the remaining ammo was fired. The variability also seems to rule out a single "sabotage round" mixed in with a batch of "good ammo". Using a faster powder with a normal fill percentage was the only way I could get results over 300% pressure. Ball powders have additives to slow down burn rates. Most likely the BSA would seem to be assembled with "bad batch" of powder with chemical decomposition that increased the effective burn rate and where the batch was non-uniform in the degradation. Next most likely would be a "loading error" where some fast powder was non-uniformly mixed in with the desired slower powder. This would most likely be something like a nearly empty powder measure had the desired slower powder dumped on top of the fast powder in the bottom.

 

[JoeTester]

Um, Ian completely accepts the whole "gun Jesus" moniker - it's not an insult. Ian has literally had "gun Jesus" merchandise that he's sold himself. Eg, its sold out at the moment but he had this poster available:

View attachment 1103482

Obviously, thats not the point. The point is that he dismisses 100% of what Mccollum has to say. That was my point.

Again the problem is: Serbu ignored all of Mccollum's advice, while saying essentially "it doesn't matter what gun jesus said." I am simply pointing out the words he used in dismissing everything brought up in Mccollum's extensive video on the subject of fail-safe designs.

To wholeheartedly ignore his advice, and not engineer into the weapoon a single designed failure point, aka a fail-safe, is utterly irresponsible.

Someone will get another overpowered 50 BMG round. And when one inevitably makes it into another RN-50, a design that has ZERO engineered intentional failure-points (aka "fail safes", a term Serbu defines incorrectly over and over in his reponses), the gun will release the excess pressure in the same direction it did before, by breaking the weakest part of the pressure containing mechanism - the threaded cap.

So please don't straw-man my argument by pretending the problem I have is the name he uses for Mccollum, and not the fact he dismisses everything Mccollum has to say.

I'm simply quoting the way in which he decides to ignore advice he should take, because as he states, his lawyers have told him he is fine. Him calling him "gun jesus" doesn't matter- as i state "he dismisses everything [Mccollum] says while calling him gun jesus"

If you think Serbu not taking any of the info or recommendations from gun jesus is correct, than that is fine. But don't present a straw-man argument pretending that I care what name he calls people; I only care that he dismisses their advice entirely, and I merely quote Serbu on what words he says when dismissing excellent advice.

Serbu could call Mccollum "the smartest gun expert I know" and my point would remain exactly the same, don't ignore exceedingly valuable advice and expertise.

 

[JoeTester]

I understand it very well. The issue isn't making the gun explosion proof, it's creating a design that handles basic failures without killing the shooter. This type of firearm design criteria has been understood and implemented for well over a century.

To those who think the RN-50 is fine as is - This quote summarizes the problem we have with the design, and Serbu's reponse to finding out (via KB's near-death experience) where the pressure escapes when the RN50 is loaded with a terribly overloaded round.

Serbu should have had a designed failure point for the pressure to escape in a different direction in the very first place with the RN-50.

And, undeniably, he should add a fail-safe after seeing what happens when an over-pressured round exceeds
the tolerances of his design.

There is no excuse for not trying to design an intentional failure point into the weapon after finding out that: the weakest point of the design is the threaded cap, and it is aimed directly at the shooter.

I am so lost as to why this is debatable. Yes the ammo is at fault - but such overloaded ammo exists, will end up in a RN-50 again. Do you truly think it's ok to leave the design as is, knowing what we know now, thanks to KB's horrific experience?

Another overloaded round is out there - and will be loaded in an RN-50. Thats undeniable, and that sucks - but I don't care about assigning blame, I care about avoiding tragedy. We can't change the fact that the bad rounds exist, but we can change things about the gun. Surely, we should do what is possible and not simply say, "well it wasn't the guns fault, so who cares".

 

[Goosey]

I watched a few videos on YouTube, most of them were focusing on the ammo, or on KentuckyBallistics' negligence.

Only this guy (posted earlier in this thread) actually analyzed the design of the rifle and its potential flaws:

 

[P Flados]

I disagree that a re-design is required. In the re-test with the Serbu design, it handled a number of gross overloads with no detectable damage. The re-test results are much more in line with what I will call typical overpressure rounds. Having this occur with nothing worse than stuck case is a good outcome. Also, with the fully enclosed breech (cap screwed directly onto the barrel) anything similar to a simple case separation is going to result in minimal hot gas blow back at the shooter. The vent holes on bolt actions are needed because the breach does not seal at all against the back of the barrel and case separation events did lead to injuries from gas blow back.

I think that those arguing for a re-design are not fully thinking through the apparent severity of the degree of overpressure. My evaluation of what it took to get these kinds of pressures indicated that you would have to use something like a case full of a Titegroup or a similar powder. I have seen other intentional gun blow ups using Titegroup. Significant injury would be likely from many of them.

When I looked at the video of what happened to the Barret, I came to the conclusion that a shooter could have easily lost an arm with potentially life threating blood loss.

If this design was for a popular gun, a high dollar re-design effort to make it "better" could be justified and the cost spread over many units. For the volumes involved, I see no "easy answer" assured to give significant improvement. Any changes without thorough evaluation could potential make things worse.

 

[D.B. Cooper]

I think that those arguing for a re-design...

I don't know about others, but I'm not arguing for a redesign; I'm arguing for the government to come in and shut the operation down. (And I'm not one to lightly or flippantly suggest that the government should get involved in the economy or industry.) That won't happen because there is no mechanism or agency to force a recall or revoke a manufacturing license. (Well, perhaps ATF could revoke Serbu's license to make and sell guns.)

At this point, I'm hoping the invisible hand of the market puts Serbu out of business. Hopefully, word of this will spread wide enough and far enough that he never sells another one and has to go out of business. This is like Ford Pinto territory.

 

[rust collector]

All have had ample opportunity to express their theories and opinions over the last three months or so. We can re-visit if there are startling new developments.