Off Topic Chat. (MOD NOTE post# 3949 and post#5279)

tudderone · 30-04-2021 12:44am

civdef wrote: »

Was just watchin that here. Yer man needs to buy a lotto ticket or two.

Not sure I like the idea of a cheaped-out 50BMG rifle where if the endcap fails it becomes a projectile -

I seen a guy who had a Blaser bolt in his face, not a cheap rifle by any stretch of the imagination. He survived, but he was deformed facially. Anything mechanical can fail, that includes rifles.

The max pressure according to the guy in the video for a .50 bmg is 55,000 psi. Those slap rounds were reckoned to be 85,000 psi. It was like firing extremely hot proof rounds (proof rounds are normally only 10% over max pressure) through that rifle.

Don't blame the rifle, it was his own doing, he was very foolhardy.

tudderone · 30-04-2021 12:47am

Cass wrote: »

Can happen with a bolt action too. Excessive pressure, bolt handle fails and bolts finds "the path of least resistance". IOW backwards.

Only thing about a bolt action, so long as catastrophic failure doesn't occur, is you can judge over pressured rounds by the bolt lift (stiff). With and end cap you wouldn't have that.

One thing that surprised me in that video is the "low" max. pressure of the gun. 50,000+ psi. I thought it's be a lot more for a 50cal as some 308s and 300winmags can produce and/or are rated for similar pressures (up to 62,000.

The bigger the round the lower the pressure. Some of the African heavy game rounds are not very high pressure at all, relatively. Force = pressure x area, so the more the area increases, the lower the pressure has to be for the same force on the action lugs etc.

Cass · 30-04-2021 1:00am

tudderone wrote: »

The bigger the round the lower the pressure. .

Yeah, seems counter intuitive though. You think bigger = more. Just surprising to me.

Mellor · 30-04-2021 2:23am

Grizzly 45 wrote: »

Ah ! The old lawyer tactic there Mellor?;)
Weak on law, argue the facts. Weak on facts ,argue the law. Weak on both , attack the character of the witness?

The old sad strawman trick Grizly. :rolleyes:

At which point did I attack his character? I pointed out he was willfully misinterpreting the statement. That's a stateman on his poor argument, not his character.
But you knew that, of course. As you are doing the same. Shocker.

But seeing that Im sure Bin Ladin and Al Queida are/were great proponents of democracy and constitutional republics...I'm sure there is some merit in your in your argument there somewhere??Just cant see it?

To be honest, I don't for one second believe you don't understand it.
I'm not going to give you credit for playing the dummy card.

Pearl Harbour 9/11 was a attack on the US. Neither of them were an attack of the US democratic process.
The fact Bin ladens isn't a proponents of democracy doesn't change the attack.

Hilter was a vegetarian. WW2 wasn't an attack people who eat meat. Can't believe I has to explain that, but here we are.

Mellor · 30-04-2021 2:38am

Feisar wrote: »

I do have a wry grin on my face when I see lads on here arguing the toss on US politics, like it matters, they're all gangsters out for themselves.

100%. Couldn't agree more with this.
The US system is completely toxic. Counter productive to anything other than making up lies and blaming the "other guys". It's a game of self promotion.

I always find it strange when people in Ireland get obsessed about their "side" over there.

Cass · 30-04-2021 9:55am

You do understand/realise you must count yourself in this given your post history and defence of "your" side on this thread? Do you have that same wry grin when you're posting?

Feisar · 30-04-2021 10:02am

Cass wrote: »

You do understand/realise you must count yourself in this given your post history and defence of "your" side on this thread? Do you have that same wry grin when you're posting?

Me? I can barely be bothered with our own politics! Although apathy is nearly as big or maybe a worse crime.

civdef · 30-04-2021 10:08am

On the rifle- I dunno folks, for about the last hundred and thirty years or so bolts/breeches have been designed to have secondary and even tertiary mechanisms to prevent catastrophic failures like this.

This RN50 rifle design has 4-5 threads on the breech cap, and nothing else (and not heavy interrupted threads like you’d see on a cannon breech either) Those lugs behind the cap could have been designed sturdy enough to provide some additional containment, but instead they just sheared off and became projectiles (and were the bits coming closest to killing the man in this case).

The RN part of the design would not inspire confidence bearing in mind some of his previous creations. Serbu himself looks to be a competent engineer, but this design looks to have centred more on low cost than anything else (and still not all that cheap!)

Mellor · 30-04-2021 11:11am

Cass wrote: »

You do understand/realise you must count yourself in this given your post history and defence of "your" side on this thread? Do you have that same wry grin when you're posting?

I wasn’t the one who mentioned a wry grin. But FWIW I don’t have a “side” in the US politics either.

I’ve criticised Trump during his term for being an imbecile, or a liar. Has nothing to do with his side of the spectrum. I just dislike liars tbh.

Similarly with that previous article. It’s far-right clickbait nonsense. The author is misrepresenting a fairly basic sentence. I don’t have to be far left to point that out, nor does doing so put me there.

Again, it’s a disdain for lying, twisting people words, and the general culture of wilfully spreading fake news that’s become common.
Nothing to do with sides. I’d call out far-left fake news just as quickly.

Cass · 30-04-2021 11:18am

Feisar wrote: »

Me?

No. My reply to Mellor and as it was directly under Mellor's post so i didn't think a quote was necessary, plus you have posted either very little to nothing at all on the US political scene on this thread.

Although apathy is nearly as big or maybe a worse crime.

Worse, and that is not a dig at you in any way, shape or form.

My biggest peeve is people that say/think "i can't be bothered". In relation to any subject/topic. Then they are surprised when real world stuff "appears" such as their oil/fuel costing 10% more, food costs more, their mortgage rates go up, property tax is introduced, Civil liberties are taken away.

Not picking a side is worse than being accused of picking the wrong side as silence/apathy gives credence and "strength" to the other side.

I don't agree with Mellor on his political view points and as this thread proves we've argued (to death some times) various topics on it, but i respect his conviction and ability to discuss it. Some posters lurk, read but never post and again if they don't want to discuss their views/beliefs but have them, that is fine. What makes me have a smug grin is those who are incapable of discussing any topic and simply sit back thanking posts because they cannot engage.

Mellor · 30-04-2021 11:32am

Cass wrote: »

Not picking a side is worse than being accused of picking the wrong side as silence/apathy gives credence and "strength" to the other side.

Just to clarify, when I said I don’t have a side in the US. I’m taking about republicans, democrats. Left, right. Whatever.
Obviously on various issues. I’ll have an opinion. Or if one “side” posts something incorrect I’ll argue the point. But that stems from the facts, correctness, etc.
Not a “side” I’ve committed to support/vote for for life.

Cass · 30-04-2021 11:33am

Mellor wrote: »

I wasn’t the one who mentioned a wry grin.

Never said you did.

But FWIW I don’t have a “side” in the US politics either.

Your post history indicates other, but i get your point. None of us have a side in US politics as we're not American (well i cannot speak for you given i don't know your location), but we can understand certain view points over others which can be seen as taking sides.

I’ve criticised Trump during his term for being an imbecile, or a liar. Has nothing to do with his side of the spectrum. I just dislike liars tbh.

You must love biden so (sense the sarcasm). A liar, imbecile, incompetent and plagiarist yet some adorn him simply because he is not the bad orange man.

Similarly with that previous article.

Don't know, didn't click on it or read it no more than i would with any far left rag/site.

Cass · 30-04-2021 11:39am

Mellor wrote: »

Just to clarify, when I said I don’t have a side in the US. I’m taking about republicans, democrats. Left, right. Whatever.
Obviously on various issues. I’ll have an opinion. Or if one “side” posts something incorrect I’ll argue the point. But that stems from the facts, correctness, etc.
Not a “side” I’ve committed to support/vote for for life.

And there is the issue at the heart of such discussions. You, and I mean the general you (including me), immediately get labeled left/right wing and everything said is either lost on the person because they don't agree with me without ever reading/understanding the content of what I'm saying.

I'm all for less Government interference, against abortion, for free speech, less taxation, Christian, and for personal accountability. If in America I'd be seen as a Republican, but that doesn't immediately mean I'm against gay marriage, against minorities, racist, fascist, anti muslim, etc. but those labels will be attached to me regardless of my beliefs on them and hence the respondent to my posts will come into the debate believing/assuming i have these beliefs and attack that, not the content of my post.

Cass · 30-04-2021 11:44am

civdef wrote: »

On the rifle- I dunno folks, for about the last hundred and thirty years or so bolts/breeches have been designed to have secondary and even tertiary mechanisms to prevent catastrophic failures like this.

They can, and do, still happen and its usually human error. I've seen, as i'm sure you have too, videos on Youtube of guns exploding because of poor maintenance and/or poor shooting practices (hot loads, wrong caliber ammo, etc).

My point is nothing is infallible.

This RN50 rifle design has 4-5 threads on the breech cap, and nothing else (and not heavy interrupted threads like you’d see on a cannon breech either) Those lugs behind the cap could have been designed sturdy enough to provide some additional containment, but instead they just sheared off and became projectiles (and were the bits coming closest to killing the man in this case).

At, according to the guy, nearly 50% over maximum pressure nothing was going to hold against that. He should have known that so that incident, not accident, was his fault.

The RN part of the design would not inspire confidence bearing in mind some of his previous creations. Serbu himself looks to be a competent engineer, but this design looks to have centred more on low cost than anything else (and still not all that cheap!)

Possibly. I'm not familiar with the make/design and my first time seeing it was on that video.

civdef · 30-04-2021 11:54am

100% agreed, with that much overload it was always going to fail and be totally banjaxed.

Looking at the design though, some relatively small changes would have helped prevent the scale of what happened here. It shouldn't have been so easy to make shrapnel out of the components and that failure mode was foreseeable in this design, I reckon.

Mellor · 30-04-2021 11:56am

Cass wrote: »

At, according to the guy, nearly 50% over maximum pressure nothing was going to hold against that. He should have known that so that incident, not accident, was his fault..

I can’t see the video. But did a google search and seen what I assume is the same video.

How was he to know it was 85kPsi though?
I’m not familiar with the tech specs if slap rounds. So maybe they are 85 by default.

It sounded to me like he was told by the manufacturer after the fact that it must have been 85k min to blow the cap. It could have been higher.

Cass · 30-04-2021 12:35pm

civdef wrote: »

It shouldn't have been so easy to make shrapnel out of the components and that failure mode was foreseeable in this design, I reckon.

Yup. Cars are designed with crumple zones, seat belts, etc. all for the worse case scenario. As you said above guns have ports and other fail safes but not all manufacturers do this and cheaper branded models would, by assumption, not have as many or any. That cap system would not be my choice anyways.

Mellor wrote: »

How was he to know it was 85kPsi though?

He said it in the video he was using slap rounds (basically sabot). As someone that reloads i know what each of my guns are rated for and most factory ammo is "lawyer friendly" so well under the maximum threshold of the guns safe working pressures. If i'm unsure i'll check and if i'm ignorant my gun will tell me with pressure signs. Flattening of the primer, excessive muzzle flash, recoil, hard extractions of spent casings, etc.

In the video he said, retrospectively, there were signs of them being hot. I got this, on a much smaller scale when using Hornady Superformance, with stiff bolt lifts, flattened primers, etc. so its why i don't use them. He should have taken more caution and stopped if in doubt.

I’m not familiar with the tech specs if slap rounds. So maybe they are 85 by default.

It sounded to me like he was told by the manufacturer after the fact that it must have been 85k min to blow the cap. It could have been higher.

Nor was i until he said so on his video. The slap round produces, according to him, 85,000 psi. He also said the gun is rated for the normal pressures of the round, iow up to 55,000 psi. Had he checked those the other way round, iow before firing, this could have been avoided.

glad he is alright. I had a similar experience some years back, but luckily for me the rifle held and i got a blurry eye for a few weeks and little more. Wasn't the round was at fault it was the rifle. Poor quality control when manufacturing it meant the headspace was huge which allowed the case to expand sideways.

Scared the living crap out of me.

BattleCorp · 30-04-2021 12:36pm

Wot video are yiz talkin about? I don't see a link on the thread.

Asus1 · 30-04-2021 12:46pm

BattleCorp wrote: »

Wot video are yiz talkin about? I don't see a link on the thread.

https://youtu.be/1449kJKxlMQ

Cass · 30-04-2021 12:53pm

BattleCorp wrote: »

Wot video are yiz talkin about? I don't see a link on the thread.

The original poster deleted his post with the video link. Asus1 has it there now so you'll see.

BattleCorp · 30-04-2021 1:10pm

Asus1 wrote: »

https://youtu.be/1449kJKxlMQ

He's a lucky lucky man.

Mellor · 30-04-2021 1:15pm

Cass wrote: »

If i'm unsure i'll check and if i'm ignorant my gun will tell me with pressure signs. Flattening of the primer, excessive muzzle flash, recoil, hard extractions of spent casings, etc.

In the video he said, retrospectively, there were signs of them being hot. I got this, on a much smaller scale when using Hornady Superformance, with stiff bolt lifts, flattened primers, etc. so its why i don't use them. He should have taken more caution and stopped if in doubt.

That’s fair enough. I had assumed that the ammo was inconsistent. And the first rounds were closer to the norm. But he did point out the muzzle flash on the second round.

Nor was i until he said so on his video. The slap round produces, according to him, 85,000 psi. He also said the gun is rated for the normal pressures of the round, iow up to 55,000 psi. Had he checked those the other way round, iow before firing, this could have been avoided.

The US army rate the 50 BMG for 54kpsi. I’d have assume that applied to the slap rounds also.

I’ll have to rewatch to double check. But I don’t think he meant that slap rounds are 85kPsi generally but rather that this round must have been 85kPsi to shear the ears and cap thread.
I thought that the 85kpsi came from a conversation with Serbu after the fact. He’s guessing 85k is the failure point. Could have been 70k, or whatever.

I assume these were reloaded rounds not factory.

glad he is alright. I had a similar experience some years back, but luckily for me the rifle held and i got a blurry eye for a few weeks and little more. Wasn't the round was at fault it was the rifle. Poor quality control when manufacturing it meant the headspace was huge which allowed the case to expand sideways.

Scared the living crap out of me.

Crap. What happened when you fired.
Thankfully nothing remotely like that for me.

Grizzly 45 · 30-04-2021 1:17pm

civdef wrote: »

Was just watching that here. Yer man needs to buy a lotto ticket or two.

Not sure I like the idea of a cheaped-out 50BMG rifle where if the endcap fails it becomes a projectile -

Wouldnt call Serbu arms cheap. Mike Serbu is pretty much a custom builder and gun engineer in Florida, and as Chris said he talked to him and the gun is normally pushing 18,000 pounds downrange.For it to strip threads and explode like that,he[Serbu] is estimating it was in the region of 80 thousand pounds of pressure

Threading is also probably one of the strongest ways of locking up anything that needs joining,as witnessed by the interrupted retractable threads on breeches on artillery pieces to speed up reloading. Just takes forever to reload by normal threading on a barrel breech. Hence it never took off as a weapons system.

Two theories what happened.[1] As it was old ammo, it's possible the nitro leaked out of the powder and the powder exploded rather than burned in a controlled manner.

2] Somewhere in the rounds life it was doctored by overloading or had pistol powder loaded into it. Going by the shot previous to the explosion, I'd tip on the latter.

BattleCorp · 30-04-2021 1:22pm

Grizzly 45 wrote: »

2] Somewhere in the rounds life it was doctored by overloading or had pistol powder loaded into it. Going by the shot previous to the explosion, I'd tip on the latter.

The lesson there being 'never fire a load that was reloaded by someone else'.

Grizzly 45 · 30-04-2021 1:22pm

Mellor wrote: »

I wasn’t the one who mentioned a wry grin. But FWIW I don’t have a “side” in the US politics either.

I’ve criticised Trump during his term for being an imbecile, or a liar. Has nothing to do with his side of the spectrum. I just dislike liars tbh.

Similarly with that previous article. It’s far-right clickbait nonsense. The author is misrepresenting a fairly basic sentence. I don’t have to be far left to point that out, nor does doing so put me there.

Again, it’s a disdain for lying, twisting people words, and the general culture of wilfully spreading fake news that’s become common.
Nothing to do with sides. I’d call out far-left fake news just as quickly.

Good! Then you'll obviously dislike Biden and his gang of liars...They havent stopped since they learned to talk obviously.

Grizzly 45 · 30-04-2021 1:28pm

BattleCorp wrote: »

The lesson there being 'never fire a load that was reloaded by someone else'.

Or more like,be very careful of old surplus ammo that you have no idea of its provenance, who owned it,what they did with it, where or how it was stored that you buy off Gunbroker.:eek:
Thinking a few sandbags and a bit of string could have made all the difference to him.

Grizzly 45 · 30-04-2021 1:29pm

Mellor wrote: »

100%. Couldn't agree more with this.
The US system is completely toxic. Counter productive to anything other than making up lies and blaming the "other guys". It's a game of self promotion.

I always find it strange when people in Ireland get obsessed about their "side" over there.

Sounds like our lot TBH as well.:) Or any Western democratic system of Govt.

Uinseann_16 · 30-04-2021 1:47pm

Grizzly 45 wrote: »

Wouldnt call Serbu arms cheap. Mike Serbu is pretty much a custom builder and gun engineer in Florida, and as Chris said he talked to him and the gun is normally pushing 18,000 pounds downrange.For it to strip threads and explode like that,he[Serbu] is estimating it was in the region of 80 thousand pounds of pressure

Threading is also probably one of the strongest ways of locking up anything that needs joining,as witnessed by the interrupted retractable threads on breeches on artillery pieces to speed up reloading. Just takes forever to reload by normal threading on a barrel breech. Hence it never took off as a weapons system.

Two theories what happened.[1] As it was old ammo, it's possible the nitro leaked out of the powder and the powder exploded rather than burned in a controlled manner.

2] Somewhere in the rounds life it was doctored by overloading or had pistol powder loaded into it. Going by the shot previous to the explosion, I'd tip on the latter.

I wouldn't call his firearms exactly high quality though, have also seen a video on one of his bolt action 50s having an absolutely horrific threading job of the barrel into the action
The RN 50 is made to be cheap and the threading should have held but if you look at the video even with the cap threaded on all the way some of the end threads didn't strip on the action which makes me think they weren't fully engaged with the end cap

tudderone · 30-04-2021 2:00pm

I seen a scene of utter devastation at a range in America i think it was. A guy had built a centrefire bench rest rifle on a Tikka action. After having it rebarrelled, he was at the range breaking the barrel in. Firing a few rounds, stopping and cleaning the barrel with a rod and jags.

He was distracted by something, someone started talking to him or the like and he forgot the rod was in the barrel. Loaded a round and fired. KA-BOOM on a grand scale. The action didn't fail, as the bolt stayed locked into the action, but as with this serbu, the threads on the barrel failed.

There were pieces of scope, scope mounts, stock, barrel, the cleaning rod etc all over the place.

There is not a massive safety factor built into firearms, there can't be or you would need two stout men and a boy to carry the thing.

Cass · 30-04-2021 2:30pm

Mellor wrote: »

The US army rate the 50 BMG for 54kpsi. I’d have assume that applied to the slap rounds also.

This is why reloaders never share ammo. What works in my rifle may not, to catastrophic effect, work in another. Even off the same make/model.

I’ll have to rewatch to double check. But I don’t think he meant that slap rounds are 85kPsi generally but rather that this round must have been 85kPsi to shear the ears and cap thread.

Thats what he said, that the cap/rifle to have failed in such a way would have required over 85k. So if it failed like that then it had to be 85+k.

I thought that the 85kpsi came from a conversation with Serbu after the fact.

It was, according to the video. My point was he should have checked before firing.

I assume these were reloaded rounds not factory.

I've no idea. He said they're hard to get and expensive as hell so its possible.

Crap. What happened when you fired.

Blinding white flash, then darkness. I had my eyes closed at this point. First thing i done was felt my face, you know, for the bolt, and when i felt nothing buy skin and fat i quickly started to "settle". I couldn't open my eye for a few hours, the sensation was like sand in it.

I had peppering of my face from the carbon of the round and redness but no cuts or open wounds. I applied eye wash and a patch. Changed this every few hours for a few days. My eyesight was unaffected but for days i had blurred vision so bad i could only see colours/light. It took a week to get shapes back and then another week to get focus.

Was blessed the bolt held and the guns' safety features done their job. It was also factory ammo which is no where near as hot as reloaded (was breaking in the barrel rather than testing loads).

Odd part is the first shot went off without a hitch, but obviously exaggerated the issue so when the second shot came, likethe guy in the video, it failed.

Shooting Forum - Firearms licencing information

Off Topic Chat. (MOD NOTE post# 3949 and post#5279)

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