[Closed] Dying to be a Youtube star?

is it half term or are the primary schools off for the holidays?

It is in most of Scotland 8)

I really don't think there should be any charges brought here! 😆

unless you can back that up with a bit of reloader chat about what primer seating tool, how often you neck down your cases and ohlins v redding you just look like somebody who knows nothing and has never fired a pistol ( a real one pre U.K. banning)

I may not have put it like that, but I agree, the 50 cal is nothing like the 357 or 44 magnum. Having shot a Desert Eagle in 357 (pre ban) it is a veritable pussycat in comparison.

The whole point of the Desert Eagle was bang for buck, it was a well thought out strategy in "how to increase gun sales by making something so utterly ridiculous people will clamber to get their hands on it" - As a firearm, especially in 50 cal, it was useless other than to be something to be feared. It's heavy, low capacity, and the rotating bolt mechanism made it prone to jamming. But fire one and it's a scary as **** looking hand cannon. It really is the penis extension they all talk about.

Anyhoo, still idiots to think a book would stop one

So care to explain it to us primary school kids?

i accept my understanding of physics is wrong (i didn’t do it at school) my understanding was based on muzzle energy in ft/lbs which i have a layman grasp of bullet weight in grains/velocity/ energy and how that drops off over 50/100/200 yards and what you can kill with it (there are laws for shooting deer where you need a certain amount of energy at a given distance)

this explains it but i still dont understand the funny numbers [url= http://www.bsharp.org/physics/recoil ]http://www.bsharp.org/physics/recoil[/url]

especially when i see what a certain amount of ft/lbs of energy at 3500fps can do and it certainly doesnt equate to what you feel at the shoulder even if i take in the weight involved. for me its like the aeroplane on a treadmill thing, it may be the correct answer but i still dont believe it!

there are still some other 'right weapons' spouting crap on this thread, i just doubt they would admit it 🙄
ninja edit: boba posted before me and is absolved

Anyhoo, still idiots to think a book would stop one

Well if we are talking about equal and opposite reactions, you can hold the gun in your hands and fire it, so I bet that means that you could hold the bullet as it comes out of the gun.

In fact, I bet even a book *would* stop it. Hang on, I've got one around here somewhere....

"Look ma, no [s]hands![/s] heart!

Of all the threads to turn into a "look at me! I've fired a gun!" thread 😆

Well if we are talking about equal and opposite reactions, you can hold the gun in your hands and fire it, so I bet that means that you could hold the bullet as it comes out of the gun.

I think it means that if you could catch the bullet in another identical gun and if you could decelerate it in the barrel at the same rate that it accelerated out of the other barrel you'd feel exactly the same kick as the guy that fired it.

If we do that experiment bagsy I do the firing not the catching.

if you held the gun in your mouth then somebody could catch the bullet in their teeth easily enough, i have seen them do this in films

I am not an expert, but have witnessed phone books stopping bullets from fairly hefty police weaponery in this country at a 'demonstration of force' event. So not quite as far fetched as it would seem; something to do with the laminar nature of the pages of a book having excellent energy absorbing properties, it was explained.

That said, I have also fired a box of rounds through a .50 desert eagle, and it was ridiculous. I also had a go with a magnum and an ak47; nowhere near as intimidating to use. The desert eagle made the entire spit n sawdust Vegas range go quiet as all the locals stopped to look and see what was being fired down range. Bonkers. 😯 I wouldn't trust 10 phone books between me and the DE.

Of all the threads to turn into a "look at me! I've fired a gun!" thread

I thought it was more the "look at me! I failed GCSE physics!" thread?

Of all the threads to turn into a "look at me! I've fired a gun!" thread

I thought it was more the "look at me! I failed GCSE physics!" thread?

Anyone got a link to the YouTube clip?

Asking for a friend

Interesting how on some threads jokes are allowed immediately, just sayin. Total f-wits both of them.

The desert eagle made the entire spit n sawdust Vegas range go quiet as all the locals stopped to look and see what was being fired down range.

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v8ninety - Member
I am not an expert, but have witnessed phone books stopping bullets from fairly hefty police weaponery in this country at a 'demonstration of force' event. So not quite as far fetched as it would seem; something to do with the laminar nature of the pages of a book having excellent energy absorbing properties, it was explained.

I'm guessing they also didn't tell you is there were using kevlar pages! 😆

jambalaya - Member
Total f-wits both of them.

interesting how insults are allowed too! 😉

I'm guessing they also didn't tell you is there were using kevlar pages!

As I understand, the energy in the round would be equal and opposite to the recoil energy

No. Momentum is conserved, not energy. The momentum of the bullet and of the gun would be equal and opposite, the bullet would have more energy.

Momentum is mass x velocity. If the gun was 100 times the mass of the bullet, then the bullet would have 100 times the velocity.

Energy is mass x velocity x velocity. The bullet would have 100 times the energy of the gun, but equal momentum. The impact of a gun's recoil won't do you serious injury, the impact of a bullet will kill you, even though they have the same momentum.

so am i right? 😕

can somebody who hasn’t failed gcse physics (i never even sat an exam) tell me that if a bullet has 2000 ft/lbs of muzzle energy and weighs 100grains is it true that the same amount of energy is forced the other way into the rifle that weighs 10lbs.
is it purely the mass that stops the equal amount of energy killing you?

maybe a nice diagram to explain, none of those funny equations

also if you bolted the gun to a 1 tonne concrete block would the bullet travel faster?

Phone book? Considering a friend put an air gun pellet* most of the way through a phone book they can't have been that powerful.

Calibre isn't everything, speed accounts for a lot as well.

*well above FAC

maybe a nice diagram to explain, none of those funny equations

Where is Bez when you really need him?

Energy is mass x velocity x velocity. The bullet would have 100 times the energy of the gun, but equal momentum. The impact of a gun's recoil won't do you serious injury, the impact of a bullet will kill you, even though they have the same momentum.

But the hypothesis was "a book that had just stopped a bullet would kill you".

also if you bolted the gun to a 1 tonne concrete block would the bullet travel faster?

Yes, if the gun was on a conveyor belt.

perchypanther - Member
Was disappointed when it wasn't Stampy Longnose.

or Dan Tedium

trust me there are far far worse

ashdub and iballistic squid

two shouting morons shouting moronically

nickc - Member
How come none of their neighbours thought it might be worth having a word? They can't all be as thick as a...book?

I feel sorry for the wife. He made her do it after convincing her it would be ok, and after doing a trial run. OK she was dim enough to believe him, but I think she should be freed.

Yes, if the gun was on a conveyor belt.

Slightly more nuanced than that.

Momentum is always conserved. But in that example the whole world could make up the other half of the equation and move (very slowly compared to the bullet).

There's then a finite amount of chemical potential energy to transfer from the gunpowder into heat/kinetic/sound energy. If the gun is assumed to not move at all (impossible but you could make this at least approach zero), then more energy must go elsewhere (i.e. the bullet) making it faster, assuming it doesn't waste more as heat or a louder bang.

It's counter productive though, you're better off absorbing some energy from a huge charge than you are trying to anchor down a smaller gun, which is why artillery have hydraulic recoil dampers rather than trying to anchor them to the ground.

which is why artillery have hydraulic recoil dampers rather than trying to anchor them to the ground.

I wonder if their 'test' was just shooting at a book standing up somewhere so the bullet didn't penetrate because the book moved instead

Remember folks, these people have exactly the same number of votes as you

I know it's wrong, but I really hope she said something like "publish this" before firing.

I am not an expert, but have witnessed phone books stopping bullets from fairly hefty police weaponery in this country at a 'demonstration of force' event.

Maybe this youtube couple had just watched that episode so thought it was a goer! I don't think the Mythbusters were shooting at point blank range though. Or at live targets.

Mythbusters armoured a car with phone books in one episode. A single layer of books was sufficient to stop handgun (9mm & magnum) rounds IIRC, and rifle rounds only required 2 layers which was pretty surprising!

But they shot at it from a distance away. This was 30cm.

From Everyday physics......I got a C in physics

Momentum characterizes an object's resistance to change in motion. If this is motion along a straight line, we call it linear momentum; if it is rotational motion we call it angular momentum. The basic idea is the same: moving things like to keep moving, and to change their motion we have to apply a force. If no force is present, then momentum doesn't change, ie. it is conserved.
Now, you might point out that a bullet coming out of a gun has a huge force on it from the exploding gunpowder. True enough, and that force is what propels the bullet forward. However, if you look at a bullet and gun together (say while the bullet is still in the barrel but already heading out at full speed), you can say there is no net force on the bullet-gun system. So the momentum of the bullet plus gun should be conserved.

If the bullet has mass mb and speed vb out of the gun, it has momentum pb given simply by

pb = mbvb

in the forward direction. To balance this momentum (and keep the net momentum of the bullet-gun system zero), the gun recoils with momentum in the opposite direction: pg = -pb, or
mgvg = -mbvb

Although the bullet's mass is small, its speed is quite large, so it released with large momentum. The gun has much larger mass, so the recoil speed is much smaller, but still large enough to give a serious kick against the shooter's shoulder.
Example: Winchester .308

Let's look at an example. A Winchester .308 cartridge launches a bullet of mass 150 grains (1 grain = 64.8 mg) with a speed of 2820 ft/s (1 ft = 30.5 cm). In MKS units, then, pb = 8.4 kg m/s. This rifle has a weight of about 8 lbs, or a mass of mg = 3.8 kg. That means the recoil speed of the rifle will be
vg = - pb/mg = -2.2 m/s

This primary recoil is noticeable, but not the main recoil that one feels.
Secondary Recoil

There are actually two distinct recoils from a gun: the first, primary recoil, which I've described above, conserves momentum of the gun-bullet system. However, a larger secondary recoil comes slightly later, when the bullet leaves the muzzle: then the hot expanding gas behind the bullet shoots out of the muzzle, and the muzzle recoils further like a rocket. This is, again, conservation of momentum, but in this case is is the gas momentum out of the barrel that makes the secondary recoil. Gun manufacturers make baffles that reduce the flow of gas out of the muzzle to reduce secondary recoil. Primary recoil cannot be reduced, since it is simply associated with the forward momentum of the bullet.
Equations

linear momentum: p = mv
Summary

The total momentum of a system is conserved if there are no outside forces acting on it.
Gun recoil results from conservation of total momentum of the bullet-gun system: the backward recoil gun momentum balances the forward bullet momentum to maintain zero total momentum.
Gun recoil actually has two parts: primary recoil from the escaping bullet and secondary recoil from the escaping gas behind the bullet.
© 2017 Samuel Hokin

I assumed that is simply a case of it being nearing impossible to fix down something of that power as to have no recoil?

This video is someone shooting a gun through books. I don't really know how the rifles they use compare to a (very powerful) handgun but a few books would probably have been OK. One book, not enough.

But they shot at it from a distance away. This was 30cm.

It was a lot more than 10ft IIRC.

I don't really know how the rifles they use compare to a (very powerful) handgun

I think rifles impart a fair bit more energy into the bullet - much more time in the barrel for the expanding gas to do its thing.

I suppose the design of the bullet would also make a difference. Some will go through things more easily than others.