Which is more effective? A large, heavy projectile with a lot of momentum travelling slower or a small, light projectile with little momentum travelling quickly?
Momentum vs velocity
Jackson Hughes
Isaiah Jenkins
Two different applications:
The small projectile at high velocity will have high penetration where the large, slow projectile with high momentum will deliver a strong, crushing blow.
Cooper Thomas
Which one is better for stopping a man?
Levi Gray
Well, a boulder flung from a trebuchet will probably "stop" a man more consistently than a .22 Eargesplitten Loudenboomer.
Isaac Phillips
Shot placement is the best guarantee!
But also, while larger is better, larger is lower capacity too and any shots missed in a stressful situation have more meaning if you don't have that many bullets left.
High capacity 9 mm pistols are very good in this respect. In fact, high capacity anything is good.
Xavier Watson
Higher speed, exponentially higher energy
Liam Baker
Unless you're Donkey Kong and you open-carry building demolition balls, definitely the former.
Dylan Gray
Formal what?
Jacob Williams
James Wood
the only hard-and-fast rule here is that higher velocity = better penetration. that's it. for everything else the answer is "it depends". Gun writers have been arguing about momentum vs. velocity vs. energy, etc, for decades and decades.
Bullet type is also hugely important. If a bullet fails to hold together long enough to hit the vitals, or if it icepicks and wastes its energy outside the target, then the rest of the numbers don't mean a damn thing.
Thomas Sanders
Force = mass * velocity^2
You should be able to figure out the rest.
Jaxon Gomez
You'd think so, but it's not that simple. There's a reason why people have been arguing this shit for a century or more.
People even invented their own scales in an attempt to solve the problem, but even those aren't universally applicable. If you're an elephant hunter you can use the Taylor KO Index, but that doesn't really apply to other things.
There's also empirical data to look at, which is nice because it fucking destroys the theory that it's all about just one factor like velocity or energy.
Mason Bennett
>Force = mass * velocity^2
That's not right.
Units of force are mass * length / (time^2)
Matthew Flores
Kinetic Energy = 1/2 * mass * velocity^2
Force = mass * change in velocity/change in time
Blake Jackson
Reasonably speaking the latter, and it really isn't a debate. Terminal effects increase drastically with velocity, the exact threshold depends on the magnitude of disruption caused by the projectile, but every projectile has a point where it'll stretch tissue too far and fast for it to handle resulting in radial wounding around the projectile path and notably improved effect on target. Flesh is considerably greater at handling increased magnitude of disruption(TSC) than it is at handling increased speed of disruption, making speed the more effective means of achieving this end per unit of increased recoil energy. For instance a .44 magnum load can produce as much or more stretching of tissue, deposit as much energy, while producing a considerably narrower wound with minimal radial tearing/hemorrhage compared to a 5.56 expanding/fragmenting round.
tl:dr within reasonable parameters and the topic at hand(bullets being used on people), speed is more effective.
Christopher Flores
>Force = mass * change in velocity/change in time
Agreed
Usually I see that second part "change in velocity/change in time" simplified as "Acceleration" though.
Force = Mass * Acceleration
F=ma
Nathaniel Wright
I'd argue for rifles; velocity is king not only for better terminal ballistics but also higher hit probability on fleeting targets. But for handguns mass is more important given limitations on how much propellant can practically be put in a sidearm cartridge and the much shorter ranges involved in defensive shooting.
Dominic Robinson
>large, crushing blow
Bullets have a momentum around that of a light blow, the crushing comes from your insides getting blown up.
Momentum does determine how well a bullet will maintain its path through some medium between you and a target such as vegetation.
Hudson Scott
You don't get shot in the barrel so the bullet has stopped accelerating (negating drag) for some time before it hits you. The force you experience (which is pretty small because bullets don't weight much) is an impulse, which is dp/dt or p/∆t for a discretized approximation.
Jacob Wright
This
Thomas Williams
If a bullet has too much velocity, doesn't hit an sure kill spot, and punches right through, then it is no where near as effective as a slower bullet that delivers most of its energy into the targets body.
Isaac Morgan
The way the OP phrased the question seemed to be a comparison of violence techniques as opposed to bullet calibers.
Logan Bailey
Correct, but having high energy is only part of it. More important is how much of the projectiles energy is transferred into the target. A high velocity round could easily penetrate though a target only leaving a clean hole with minimum loss in velocity (IE: energy)
Ryan Morales
Trebuchet. He he he.
Isaac Butler
A high velocity round that will tumble or fragment.
Carter Lewis
Until we reach the autocannon/artillery range the momentum of any caliber is pretty negotiable though.
Hunter Cook
If there was a limit on how much force I could put out with a cartridge id rather have the fast and light ammo because it would be easier to hit a distant target than with slower and heavier ammo. Also carrying more powder is much easier than carrying more lead. Heavier and slower bullets do have some applications though, atm I can only think of one. If youre shooting through bushes a heavier bullet's path is less affected by anything in its way. Thats just my retard ape opinion.
Kayden Thomas
>thinking bullet decelerate as soon as they leave the barrel
Kek
Ethan Brooks
>thinking that not accelerating and decelerating are the same thing
Owen Williams
Bullets decelerate and accelerate inside the barrel and once they are out of the barrel they only decelerate.
Wyatt Hughes
That's the fakest gif I've ever seen
Ian Stewart
I think there is still some acceleration after leaving the barrel.
Nathan Lee
Well you've always got gravity pulling it down but forward acceleration from gas pressure gonna be minimal.
Samuel Johnson
Flamethrower
Leo Lewis
>The small projectile at high velocity will have high penetration
Penetration derives from bullet weight and bullet construction. Velocity has zilch to do with it.
People are vulnerable to shock. Also, high vel rounds make huge nasty wounds. If you had to pick between a .45 LC and a .223 for defense, choose the latter... but I wouldn't want to be shot by either.
Aiden Collins
ITT: everyone parrots paul harrell
William Watson
Speed kills.
But mass has its own appeal as well.
Charles Stewart
Untrue
Jonathan Smith
K=1/2mv2
Jonathan Evans
total energy ≠ energy applied to target
Gavin Garcia
>The small projectile at high velocity will have high penetration where the large, slow projectile with high momentum will deliver a strong, crushing blow.
If you're looking at identical projectiles, then you'll find that penetration scales linearly with the speed, not quadratically. ie it depends on the momentum, not the energy. An overall "light and fast vs slow and heavy" comparison is worthless, you have multiple independent variables there possibly pulling in different directions to different degrees, so the only possible answer is "it depends".
This is also something that must be remembered. Some amount of the bullet''s kinetic energy won't do anything to harm the target, it'll just be lost as harmless friction heat. How much exactly is damn near impossible to say, and so we can't calculate any simple expression for how much damage some amount of energy will actually do. But what we can say is that drag increases very quickly with the speed, meaning that the faster the bullet goes the less efficient it will be about using its energy to do damage.
Aiden Lopez
need some projectiles with the ballistics of FMJ but with the expansion of hollow points
Carter Foster
>Penetration derives from bullet weight and bullet construction. Velocity has zilch to do with it.
Utter nonsense.
Nicholas Myers
correct, mostly
K=1/2mv2
similer to the relationship of watts being volts x amps
weight alone is nothing, and velocity alone is nothing, only the two combined do you get
force
Better wording would be a sharp fast projectile would be prone to penetration vs a slower heavier projectile would be more pron to transfer more of its energy into the target
TL;DR: fast and small for armor piercing etc, and slow and heavy for un armored and close range
also something to be said about range, heavy and slow would have piss poor ballistic accuracy at range
TL;DR: TL;DR: shits way more complicated then mass vs speed
Anthony Green
That's pretty trivial, just cast them from an alloy that's 75 wt% lead, 12 wt% antimony, 7 wt% terbium and 12 vol% unicorn spunk.
Ryan Edwards
is this a thing?
Austin Butler
>unicorn spunk
Matthew Phillips
>K=1/2mv2
Kinetic energy is not penetration, nor does penetration scale with the kinetic energy. If you want to wave around physics to "prove" your point then it helps to actually know some physics first.
Lucas Foster
>Kinetic energy is not penetration
again, not on its own no
penetration is a factor of "sharpness" of the projectile, the properties of the target AND kinetic energy
Adam Ward
On physics, there exist a thing called linear momentum, usually only called momentum. You calculate it by multiplying the velocity and mass.
P = v * m
Despite being far less well known than kinetic energy (far less widely taught in school for example), for most collisions it's often a far more important for what happens than the energy. This isn't just because nature is absolute about preserving momentum while kinetic energy can easily be transformed into other forms of energy, but also because a lot of behaviour simply depends on momentum rather than energy. For example if we take a bullet and increase the velocity by 10% then the omentum also goes up by 10%, while the energy goes up by 21%. The penetration will go up by 10% or slightly less, it won't go up by 21%.
So even in the best case scenario the connection is between penetration and momentum, not penetration and energy.
Stuff that might be good for you to read:
en.wikipedia.org
en.wikipedia.org
rathcoombe.net
Kevin Campbell
>the connection is between penetration and momentum, not penetration and energy.
PROTIP: momentum is energy, specifically Kinetic energy, you look it up sometime:
Isaiah Roberts
Wow you guys must have had a lot of trouble with high school physics, huh? Assuming a fixed amount of powder propelling two different masses of bullet, the heavier of the two will have higher momentum than the light one, though they both have the same kinetic energy.
However, faster (lighter) bullets can have better ballistics and armor penetration so there's no simple answer. Just remember that the kinetic energy of your bullet depends solely on the amount of powder behind it (and a few silly things like friction that physicists get off on ignoring).
Adam Phillips
Think about it a little bit, tho:
1kg block moving at 2 m/s
2 kg • m/s momentum
4 joules of kinetic energy
4 kg block moving at 1 m/s
4 kg • m/s momentum
4 joules of kinetic energy
Same exact energy in both cases, but one has twice the momentum.
Benjamin Nelson
It's all about distributing energy on the target, which is why explosive tipped rounds should be used. This will help with armored targets as well.
Jacob Morgan
Momentum isn't energy, it's the time integral of force. P=S(F • dt). Or F = dP/dt. That's the change in momentum with respect to time. This also leads to my favorite expression:
dtF = dP
Kayden Allen
PEOPLE THROWIN' AROUND FORCE, ENERGY, AND MOMENTUM LIKE THEY'RE ALL THE SAME THING GONNA GIVE ME A GODAM CORONARY.
Jordan Brown
I don't really understand terminal ballistics and I want to know why many people readily recommend .44 magnum as a bear round, but freak out when someone decides to use a ~20" AR. Wouldn't heavier loads easily penetrate through tissue and fragment regardless? I have been told multiple times that the round will literally stop in subcutaneous fat and not reach any vital organs, but no one has provided evidence.
Adrian Wilson
You're both right.
His is about conservation of momentum, yours is about angular momentum
Luis Miller
*Yours is about power not force. Any work done over a time period is power
Jordan Turner
penetration is positively correlated with velocity, suck it fags
Wyatt Cooper
>Penetration derives from bullet weight and bullet construction. Velocity has zilch to do with it.
velocity may have little impact to the equation but in this context it does.
a 120gr 9mm projectile going at 900fps will penetrate skin and break bone while the same going at 9fps will do jack shit to denim and will not even break skin.
even super hot shooting airshit will embed 6gram pellets into your skin and chip teeth
Christopher Evans
Momentum is a more telling sign of penetration than energy. As related to guns, the easiest fastest way to measure momentum is through powerfactor (pf) which is a popular metric in competition.
pf=mass (in grain) * velocity (in fps) / 1000.
When you begin using momentum youll start noticing trends in ballistic gel when using pistol velocity cartridges but it's important to make accurate comparisons.
>different jhp models or of different weights expand at different rates affecting penetration
>different fragmenting bullets fragment at different rates into different sizes affecting penetration
>round nose fmj and truncated tumbles at different rates, sometimes not even consistent from shot to shot, affecting penetration because of the increased surface area and possible changes in direction
>different cartridges can be different widths and the greater surface area affects penetration negatively even if higher momentum/energy
>flat nose bullets that dont tumble or deform take out the extra variables so that it's just weight and speed
Flat nose fmj of the same diameter but higher momentum but possibly less energy penetrate deeper will be a trend.
As to why using a 5.56 rifle is bad for bear compared to a 44 mag:
Go watch a youtube video of a 5.56 fmj or soft point from a 20" and see how deep it penetrates gel versus a 44 mag shooting something like a heavy wadcutter. The 5.56 will fragment and lose its momentum not penetrating exceptionally far while the 44 mag holds together and keeps pushing through.
Isaiah Young
nigga u dumb
Levi Brooks
Effective at what?
Armor penetration favors speed. Stopping power favors mass until the speeds are stupidly high, then it doesn't matter.
Long distance will also favor speed. Quiet boys will obviously favor mass, as you can't go supersonic.
There is no universal solution, just the right tool for the job.
Kevin Moore
It was probably a school project
Nathaniel Williams
F=ma
If they have the same ratio of difference, product (F) will be the same. A 100g projectile going 500m/s^2 will have the same F (inertia) has a 500g projectile going 100m/s^2.
KE=1/2m*v^2
For terminal ballistics, assuming the projectile can transfer 100% of its energy, then a faster projectile with less mass is likely more energetic than a slower one with more mass.
A 80kg person standing on Earth has the inertia of F= 80kg*9.8m/s^2, so F= 784 N.
So you need 784 N of force transferred to move an 80kg person standing at sea level.
Someone better at physics correct me if I'm wrong.
Landon Sanchez
Jow Forums becoming /sci/ is pretty damn great