THE ACCURATERELOADING.COM MEDIUM BORE RIFLE FORUM

Accuratereloading.com    The Accurate Reloading Forums    THE ACCURATE RELOADING.COM FORUMS  Hop To Forum Categories  Rifles  Hop To Forums  Medium Bore Rifles    For you folks favoring momentum over energy...
Page 1 2 3 4 5 6 7 8 

Moderators: Paul H
Go
New
Find
Notify
Tools
Reply
  
For you folks favoring momentum over energy...
 Login/Join
 
One of Us
Picture of vapodog
posted
I haven't seen anyone posting what they think a minimum of "momentum" would be for deer hunting.....or elk hunting...

Since so many prefer to measure momentum, I thought you might want to share your thoughts on the minimum momentum required for our favorite North American hunts.


///////////////////////////////////////////////////////////////////////////
"Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery."
Winston Churchill
 
Posts: 28849 | Location: western Nebraska | Registered: 27 May 2003Reply With Quote
one of us
posted Hide Post
71 lookers and ZERO responses. Wonder where they all went? Maybe they had so much Momentum that it carried them into another dimention. rotflmo animal rotflmo

Since it is all about Shot Placement( rotflmo animal rotflmo ) obviously Energy at the Point-of-Impact and Momentum have no bearing at all on Killing - unless it is a Human Wound Study. rotflmo animal rotflmo
 
Posts: 9920 | Location: Carolinas, USA | Registered: 22 April 2001Reply With Quote
One of Us
posted Hide Post
Momentum is an important component of John Taylor's Knock Out (KO) values, and General Hatcher's Relative Stopping Power (RSP) formulas. It's importance can be evaluated by answering the following questions:

1) What has a kinetic energy of 68 ft.lbs.?
2) What has a momentum of 38 lb.s.?
3) What has a KO of 109?
4) What has a RSP of 3480?

For reference, the four values for the standard high velocity .22 Long Rifle are: 147, 7, 1.6, and 1, respectively. For the .700 Holland & Holland they are: 8880, 286, 200, and 1538, respectively.

I will return with the answers to the questions after a few of you have scratched your heads over them for a while.

Cheers, Al
 
Posts: 118 | Location: New Brunswick | Registered: 03 February 2005Reply With Quote
Moderator
Picture of jeffeosso
posted Hide Post
I start with 300 grs at something over 2200 fps. Past that, deer and elk aren't really tough are they?


#dumptrump

opinions vary band of bubbas and STC hunting Club

Information on Ammoguide about
the416AR, 458AR, 470AR, 500AR
What is an AR round? Case Drawings 416-458-470AR and 500AR.
476AR,
http://www.weaponsmith.com
 
Posts: 38379 | Location: Conroe, TX | Registered: 01 June 2002Reply With Quote
one of us
Picture of Blacktailer
posted Hide Post
quote:
Originally posted by vapodog:
I haven't seen anyone posting what they think a minimum of "momentum" would be for deer hunting.....or elk hunting...

Since so many prefer to measure momentum, I thought you might want to share your thoughts on the minimum momentum required for our favorite North American hunts.

Can't answer unless you define which deer and which elk.
Are we talking 100lb blacktail or 250lb mule deer? Tule elk or Roosevelt?
I would research this further but I don't have the "energy" rotflmo


Have gun- Will travel
The value of a trophy is computed directly in terms of personal investment in its acquisition. Robert Ruark
 
Posts: 3828 | Location: Cave Creek, AZ | Registered: 09 August 2001Reply With Quote
One of Us
Picture of Wstrnhuntr
posted Hide Post
I must have missed the memo, whats all the fuss about "momentum"? Is that the new replacement word for "velocity" or what?
 
Posts: 10112 | Location: Tooele, Ut | Registered: 27 September 2001Reply With Quote
One of Us
Picture of Wstrnhuntr
posted Hide Post
quote:
Originally posted by ClassicAl:
Momentum is an important component of John Taylor's Knock Out (KO) values, and General Hatcher's Relative Stopping Power (RSP) formulas. It's importance can be evaluated by answering the following questions:

1) What has a kinetic energy of 68 ft.lbs.?
2) What has a momentum of 38 lb.s.?
3) What has a KO of 109?
4) What has a RSP of 3480?

For reference, the four values for the standard high velocity .22 Long Rifle are: 147, 7, 1.6, and 1, respectively. For the .700 Holland & Holland they are: 8880, 286, 200, and 1538, respectively.

I will return with the answers to the questions after a few of you have scratched your heads over them for a while.

Cheers, Al



Knock out value? RSP value?? Apparently I must have been napping while energy got re-invented.. Roll Eyes
 
Posts: 10112 | Location: Tooele, Ut | Registered: 27 September 2001Reply With Quote
One of Us
posted Hide Post
Wstrnhuntr:

You must be either a youngster, or just don't hang out in the right forums Wink. People have been dissatisfied with energy as a measure for firearms effectiveness for a long time. When I was in high school in the early '70s the late, great, Elmer Keith was proclaiming momentum as a better measure than energy. John Taylor is the dean of African hunters. He introduced KO values in his book "African Rifles and Cartridges", copyright 1948. He lists KO values in his ballistics tables, and states (on p. 210) that "No rifle showing less than 40 K-O values can really be considered safe for use in thick cover, at any rate if elephant are on your list." As I understand it, Hatcher's RSP formula was designed to mathematically 'prove' the superiority of the .45 ACP over the 9mm Parabellum for military purposes, at around the same time period. More recent formula such as EEE (estimated effective energy) and OGW (optimum game weight) values don't seem to have caught on.

You will see what I'm getting at when I reveal the answers to my questions.

Cheers, Al
 
Posts: 118 | Location: New Brunswick | Registered: 03 February 2005Reply With Quote
One of Us
Picture of someoldguy
posted Hide Post
quote:
1) What has a kinetic energy of 68 ft.lbs.?
2) What has a momentum of 38 lb.s.?
3) What has a KO of 109?
4) What has a RSP of 3480?


Just a guess but maybe a baseball?

About momentum and energy, IMO these have to be put into their proper perspective. Even caliber has to be put into its proper perspective. For instance, commonsense says that no one would likely think twice about hunting cape buffalo with a .45 caliber rifle. (.458 Lott, Win Mag, etc.) But how about with a .45 handgun? (.45 Colt, ACP, etc.)
But I'm afraid when you try to combine either of the two, as these exalted gun gurus of the past have done with TKOs, RSPs, etc., all you get is junk science.


_________________________

Glenn

 
Posts: 942 | Location: Alabama | Registered: 16 July 2007Reply With Quote
One of Us
Picture of MikeBurke
posted Hide Post
The only reason Taylor's formula is drug in to these senseless arguments is for years most gun writers have not had an original thought and have resorted to criticizing things they do not understand no matter how simple.

Plain and simple Taylors TKO was a way to gage how long a round could knockout a heavy massive boned animal (elephant) with a near miss to the brain. It offered an instant comparison between rounds for "actual punch". He also backed up this theory with field experience.

He even states energy is a more reliable guide for a rifle's effectiveness on soft skin game (like deer and elk size animals).

So whether you agree with the TKO or not it was never meant for deer and elk size game.
 
Posts: 2950 | Registered: 26 March 2008Reply With Quote
One of Us
Picture of bartsche
posted Hide Post
quote:
Originally posted by Mike70560:
T
He even states energy is a more reliable guide for a rifle's effectiveness on soft skin game (like deer and elk size animals).

So whether you agree with the TKO or not it was never meant for deer and elk size game.

tu2roger tu2


Old age is a high price to pay for maturity!!! Some never pay and some pay and never reap the reward. Wisdom comes with age! Sometimes age comes alone..
 
Posts: 10226 | Location: Temple City CA | Registered: 29 April 2003Reply With Quote
One of Us
Picture of chuck375
posted Hide Post
quote:
Originally posted by Mike70560:
The only reason Taylor's formula is drug in to these senseless arguments is for years most gun writers have not had an original thought and have resorted to criticizing things they do not understand no matter how simple.

Plain and simple Taylors TKO was a way to gage how long a round could knockout a heavy massive boned animal (elephant) with a near miss to the brain. It offered an instant comparison between rounds for "actual punch". He also backed up this theory with field experience.

He even states energy is a more reliable guide for a rifle's effectiveness on soft skin game (like deer and elk size animals).

So whether you agree with the TKO or not it was never meant for deer and elk size game.


Agree, and from what I've read (not experienced) the TKO seems to be pretty relevant on cape buffalo as well. You hear accounts from many PHs of the effect a 500 NE or 500 Jeffery has with a good hit compared to a 375 or 416 with the same shot placement. They will all kill, the question is how fast, and how far the animal will go (or charge) before dying.


Regards,

Chuck



"There's a saying in prize fighting, everyone's got a plan until they get hit"

Michael Douglas "The Ghost And The Darkness"
 
Posts: 4712 | Location: Colorado Springs | Registered: 01 January 2008Reply With Quote
One of Us
Picture of someoldguy
posted Hide Post
quote:
The only reason Taylor's formula is drug in to these senseless arguments is for years most gun writers have not had an original thought and have resorted to criticizing things they do not understand no matter how simple.


I agree. Taylor's formula has frequently been taken completely out of the context in which it was intended. That's when it becomes junk science. So in this case it wasn't the particular "gun guru's" fault at all.


_________________________

Glenn

 
Posts: 942 | Location: Alabama | Registered: 16 July 2007Reply With Quote
One of Us
Picture of jwp475
posted Hide Post
Taylor came up with a formula to match his field observations. His formula was never science.


_____________________________________________________


A 9mm may expand to a larger diameter, but a 45 ain't going to shrink

Men occasionally stumble over the truth, but most of them pick themselves up and hurry off as if nothing had happened.
- Winston Churchill
 
Posts: 5077 | Location: USA | Registered: 11 March 2005Reply With Quote
One of Us
posted Hide Post
O.K. what is the answer to the question?


Molon Labe

New account for Jacobite
 
Posts: 631 | Location: SW. PA. | Registered: 03 August 2010Reply With Quote
one of us
Picture of D Humbarger
posted Hide Post
momentum is energy



Doug Humbarger
NRA Life member
Tonkin Gulf Yacht Club 72'73.
Yankee Station

Try to look unimportant. Your enemy might be low on ammo.
 
Posts: 8342 | Location: Jennings Louisiana, Arkansas by way of Alabama by way of South Carloina by way of County Antrim Irland by way of Lanarkshire Scotland. | Registered: 02 November 2001Reply With Quote
One of Us
posted Hide Post
Simply speaking, momentum of an object (p) is defined as the product of the mass (m) and velocity (v) of the object.
Momentum can be considered the "power" when an object is moving, meaning how much force it can have on another object.
..an object with a large mass and low velocity can have the same momentum as an object with a small mass and large velocity.
For eg; a bowling ball (large mass) pushed very slowly (low velocity) can hit a glass door and not break it, while a baseball (small mass) can be thrown fast (high velocity) and break the same window.
Energy also possessed mass, as when energy is added to a body of matter, the mass of the body increases.
All matter has the property of mass, but not all mass has the property of matter.
 
Posts: 9434 | Location: Here & There- | Registered: 14 May 2008Reply With Quote
One of Us
posted Hide Post
quote:
Originally posted by chuck375:

Agree, and from what I've read (not experienced) the TKO seems to be pretty relevant on cape buffalo as well. You hear accounts from many PHs of the effect a 500 NE or 500 Jeffery has with a good hit compared to a 375 or 416 with the same shot placement. They will all kill, the question is how fast, and how far the animal will go (or charge) before dying.



At least on Water buffalo - and some very big bodied one's, I have certainly seen the effect of a good hit by one of the 500's (500NE, 505Gibbs,) as opposed to the sub 500's - 470NE and below.

I have actually seen the ripple effect travel along the body of a Buffalo when hit with a 500NE.

.
 
Posts: 3191 | Location: Victoria, Australia | Registered: 01 March 2007Reply With Quote
One of Us
Picture of vapodog
posted Hide Post
quote:
Originally posted by D Humbarger:
momentum is energy
tu2


///////////////////////////////////////////////////////////////////////////
"Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery."
Winston Churchill
 
Posts: 28849 | Location: western Nebraska | Registered: 27 May 2003Reply With Quote
One of Us
posted Hide Post
An projectile can have less energy than another, but more momentum..
An projectile can have more energy than another but less momentum.
An projectile can have the same energy and momentum as another but still have different level of penetration.
An projectile can have less momentum than another but still penetrate further than a higher momentum projectile.
An projectile with a whole heap of energy- without sufficient momentum, wont kill your beast.
 
Posts: 9434 | Location: Here & There- | Registered: 14 May 2008Reply With Quote
One of Us
posted Hide Post
We have a winner!

Obviously, a number of projectile/velocity combinations could answer each individual question. For example, the kinetic energy is about that of a .22 Short, the momentum that of a 117 gr. .25-35 or .25 Rem, the KO somewhere between a .505 Gibbs and a .577-3" NE, and the RSP about that of the WWII Russian 20mm ShVAK aircraft cannon.

However, Someoldguy hit the nail on the head. The combination that answers all 4 questions is a 1970s vintage regulation baseball (2.905" diameter, 2240 gr. weight) at 80 mph (117.3 fps).

If momentum equalled killing power, most of us who grew up playing ball in North America would have been dead long ago, and professional hunters would be putting aside their .450+ bores for a sack of baseballs when they ventured into the thickets after dangerous game! We're not, and they don't, so momentum and momentum based formulae are out as the best definers of projectile effectiveness.

This is where you are probably expecting me to spout off my own theory. If so, I'm going to disappoint you. I don't have the foggiest idea how to mathematically quantify a projectile's effectiveness for hunting purposes. It's too complex, and my mathematical skills are too limited. However, what I have learned over the years is that while a theory may be flawed, the observations behind that theory can still be invaluable. So, if I ever get the opportunity to hunt bigger game, I will follow the lead of Keith, Taylor, et al, and use a bigger bullet. (For the record, for deer hunting I use a .280 Rem. in the open and a .358 Win. in the woods).

Happy Hunting!

Cheers, Al
 
Posts: 118 | Location: New Brunswick | Registered: 03 February 2005Reply With Quote
One of Us
posted Hide Post
Great topic.
First and most important, MOMENTUM IS NOT ENERGY. Energy is the bang, flash,rotational energies,heat(friction)

Momentum determines THE AMOUNT OF FORCE which an bullet has available to it for penetration

Momentum has both amplitude (an ‘amount’ value) and a direction. Because any measurement of momentum has a specified direction it quantifies the net force acting in that single, straight line, direction. Momentum is, therefore, known as a linear function, and is a measurement of the force of forward movement of an object.

KINETIC ENERGY: When an object is in motion, it has kinetic energy. Kinetic energy is defined as the total energy of a body in motion. Kinetic energy is scalar, or non-directional, in nature - it is the TOTAL energy, of all types, in all directions. That is: kinetic energy has magnitude, but it does not have direction. (Note that kinetic energy is defined as ENERGY, not as FORCE.)

Momentum is a resistance to change in motion, you could think straight line penetration.

You derive momentum as Mass X Vel. How you get your momentum is important do you get it from mass or velocity.

So in order to make minimum momentum regulations work for both the hunter and the animal would be to regulate minimum weight of bullets (mass)

The baseball illustration is a perfect example, kinetic energy only tells you how hard the baseball will strike, nothing to do with penetration, that's why we're all still alive today. But just for fun, turn that baseball, into a pointy stick and propel it at the same velocity, I bet there would be penetration, but we've just moved to sectional density, sorry.

Momentum = penetration (as long as the momentum is derived from a good amount of mass)

And as the animals get bigger the evidence supporting momentum becomes even apparent. A bullet that is more resistant to a change in its direction is what one wants.
 
Posts: 457 | Location: NW Nebraska | Registered: 07 January 2007Reply With Quote
One of Us
Picture of jwp475
posted Hide Post
quote:
Originally posted by slim buttes:
Great topic.
First and most important, MOMENTUM IS NOT ENERGY. Energy is the bang, flash,rotational energies,heat(friction)

Momentum determines THE AMOUNT OF FORCE which an bullet has available to it for penetration

Momentum has both amplitude (an ‘amount’ value) and a direction. Because any measurement of momentum has a specified direction it quantifies the net force acting in that single, straight line, direction. Momentum is, therefore, known as a linear function, and is a measurement of the force of forward movement of an object.

KINETIC ENERGY: When an object is in motion, it has kinetic energy. Kinetic energy is defined as the total energy of a body in motion. Kinetic energy is scalar, or non-directional, in nature - it is the TOTAL energy, of all types, in all directions. That is: kinetic energy has magnitude, but it does not have direction. (Note that kinetic energy is defined as ENERGY, not as FORCE.)

Momentum is a resistance to change in motion, you could think straight line penetration.

You derive momentum as Mass X Vel. How you get your momentum is important do you get it from mass or velocity.

So in order to make minimum momentum regulations work for both the hunter and the animal would be to regulate minimum weight of bullets (mass)

The baseball illustration is a perfect example, kinetic energy only tells you how hard the baseball will strike, nothing to do with penetration, that's why we're all still alive today. But just for fun, turn that baseball, into a pointy stick and propel it at the same velocity, I bet there would be penetration, but we've just moved to sectional density, sorry.

Momentum = penetration (as long as the momentum is derived from a good amount of mass)

And as the animals get bigger the evidence supporting momentum becomes even apparent. A bullet that is more resistant to a change in its direction is what one wants.



+1........ tu2


_____________________________________________________


A 9mm may expand to a larger diameter, but a 45 ain't going to shrink

Men occasionally stumble over the truth, but most of them pick themselves up and hurry off as if nothing had happened.
- Winston Churchill
 
Posts: 5077 | Location: USA | Registered: 11 March 2005Reply With Quote
One of Us
Picture of Kabluewy
posted Hide Post
 
Posts: 12818 | Registered: 16 February 2006Reply With Quote
One of Us
Picture of 900 SS
posted Hide Post
I dont think I have ever have used momentum or energy figures to choose one load/cartridge over another.
 
Posts: 408 | Location: Bardu, Norway | Registered: 25 August 2007Reply With Quote
One of Us
Picture of someoldguy
posted Hide Post
quote:
This is the stuff of the ages. It was figured out long ago. Why is it a matter of such debate?


'Cause maybe the old guys were wrong. Big Grin
I suppose we're just having an armchair discussion really.

quote:
However, Someoldguy hit the nail on the head. The combination that answers all 4 questions is a 1970s vintage regulation baseball (2.905" diameter, 2240 gr. weight) at 80 mph (117.3 fps).


The baseball is one of my favorite examples. That's how I guessed. But in my example my baseball goes 100 mph or 147 fps. I've got a fast pitcher, but he tends to throw wild. Big Grin

Some that disagreed with me elsewhere over kinetic energy and penetration will want to throttle me over this. But if you want a very rough (I won't say "ballpark") idea of the penetration potential of a baseball, take the momentum (38 ft-lbs/sec) and divide by the square of the diameter. (38 / 2.905 / 2.905 = 4.5) What you get is called the momentum density. If you want to compare this to a 0.177", 5.75 grain BB going 590 fps:
5.75 / 7000 / .177 / .117 = 15.5.
Does this mean the BB will go over 3 times as deep as the baseball? I dunno. But BB's generally go over 3 inches in properly calibrated ballistic gelatin. I would guess that all you'd get with a baseball is some compression and then it would bounce off instead of sticking in.


_________________________

Glenn

 
Posts: 942 | Location: Alabama | Registered: 16 July 2007Reply With Quote
one of us
posted Hide Post
Im not much of a believer in any mathematical way to rate a guns effectiveness on game. Be it energy if ftlbs or momentum. Just seen to many times where a gun that met the numbers did pourly or one that didnt that worked fine. Just to many variables that are more important like bullet construction and bullet placement. A kind of way out there comparison would be something like a 223 using nos partitions on deer would i my opinion dump deer faster then a 458mag using solids. Ive shot deer with both and about know this to be true. Now change that solid out for something like a 405 corelock that was designed for the 4570 and then watch the deer get driven into the ground. then you have to factor in range. Take something like my 264mag at 400 yards and compare it to a 375h&h at the same range and ill guarantee the 264 will dump deer faster. Now step up in game size and everything changes. There is no accurate way to rate differnt calibers performance on game unless you just go out and try them.
 
Posts: 1404 | Location: munising MI USA | Registered: 29 March 2002Reply With Quote
One of Us
posted Hide Post
Just to throw a spanner in the works:- I am not sure of the momentum and energy figures, but 567 grains at 240 fps is just as deadly as any of the above, provided it is placed properly through heart and both lungs, and as long as the broadhead up front is razor sharp! AND:-
if you throw the spanner hard enough that would probaly work too!
 
Posts: 424 | Location: Australia | Registered: 11 August 2007Reply With Quote
One of Us
Picture of JabaliHunter
posted Hide Post
quote:
Originally posted by ClassicAl:
If momentum equalled killing power, most of us who grew up playing ball in North America would have been dead long ago,

Just out of curiosity, what are the prospects for a guy being hit exactly on the side of the temple and taking the full force of a baseball at 80mph (not a glancing blow)? A knock out for sure... maybe a good chance of death from brain haemorrhage? Any doctors in the house?
Granted, I would not expect it to have the same effect on an elephant... Wink
 
Posts: 712 | Location: England | Registered: 01 January 2010Reply With Quote
One of Us
Picture of someoldguy
posted Hide Post
quote:
Just out of curiosity, what are the prospects for a guy being hit exactly on the side of the temple and taking the full force of a baseball at 80mph (not a glancing blow)? A knock out for sure... maybe a good chance of death from brain haemorrhage? Any doctors in the house?
Granted, I would not expect it to have the same effect on an elephant...



I remember hearing a news story about a man who was killed a few years ago when he took a baseball hit to the temple. I think it was considered a freak occurrence, but still tragic.
I was talking to some medics some time back after an injury at a softball field. One expressed the opinion that a person might succumb by taking a direct blow to the heart by a baseball. Made sense when he explained it.
Even when something doesn't penetrate, it still transfers force to whatever it hits, obviously. Apply enough force and I guess you could stop a person's, or an animal's, heart.
But none of that is enough for me to want to carry baseballs in the field. (Unless it's a baseball field.)


_________________________

Glenn

 
Posts: 942 | Location: Alabama | Registered: 16 July 2007Reply With Quote
One of Us
Picture of vapodog
posted Hide Post
quote:
One expressed the opinion that a person might succumb by taking a direct blow to the heart by a baseball.

A small number of small kids are killed by direct hits to the chest from softballs hit hard by batters every year.....this is nothing new....


///////////////////////////////////////////////////////////////////////////
"Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery."
Winston Churchill
 
Posts: 28849 | Location: western Nebraska | Registered: 27 May 2003Reply With Quote
One of Us
posted Hide Post
quote:
Just to throw a spanner in the works:- I am not sure of the momentum and energy figures, but 567 grains at 240 fps is just as deadly as any of the above, provided it is placed properly through heart and both lungs, and as long as the broadhead up front is razor sharp!


Interesting comment! My computer spits out 73 ft.lb. of Ek and 19 lb.s. of momentum, so essentially the same energy as my baseball and half the momentum; but obviously much more effective. If I remember correctly from my son's years in Olympic-style archery, a hunting arrow is about 3/8" in diameter. If so, your arrow has a sectional density of about 0.73 lb./sq.in. In contrast, my baseball has a whopping SD of 0.05 lb./sq.in. So it seems that perhaps a high SD can compensate for low energy or momentum stir.

I only remember getting hit in the head once while playing ball, but that was from behind by a 'misthrown' ball while running to 3rd base. Between ball cap, hair (actually had some then Frowner), and what I am told is a thick skull, no apparent damage was done. I just got to 3rd a bit faster than planned, and with a bit of a headache! That said, I would not volunteer to be the test subject in a "fastball to the temple" test!

Cheers, Al
 
Posts: 118 | Location: New Brunswick | Registered: 03 February 2005Reply With Quote
one of us
posted Hide Post
quote:
Originally posted by ClassicAl:
... I just got to 3rd a bit faster than planned, ...
That is a Classic - Al! Big Grin
 
Posts: 9920 | Location: Carolinas, USA | Registered: 22 April 2001Reply With Quote
One of Us
posted Hide Post
quote:
Originally posted:
..The baseball illustration is a perfect example, kinetic energy only tells you how hard the baseball will strike, nothing to do with penetration, that's why we're all still alive today. But just for fun, turn that baseball, into a pointy stick and propel it at the same velocity, I bet there would be penetration, but we've just moved to sectional density, sorry.

..and turn the pointy stick into a shorter section of copper rod, with same ratio of mass to cross sectional area [ie;same SD],
and you will have a projectile that tracks better and penetrates more.
...use Tungsten[about 3x the molecular/atomic weight of copper] to create a smaller dia. projectile of same weight and SD, and it will penetrate better still.
...the only good thing about energy is that the heat from such increases the mass of a projectile.... Big Grin
 
Posts: 9434 | Location: Here & There- | Registered: 14 May 2008Reply With Quote
new member
posted Hide Post
My first priority has always been to hit them first...
 
Posts: 12 | Registered: 03 March 2011Reply With Quote
One of Us
Picture of jwp475
posted Hide Post
quote:



You are exactly right, it all goes back to Newton's 3 laws of motion.

I doubt that these internet key board commando experts will even click on the links provided.

So I'll post one of them:


quote:
http://csep10.phys.utk.edu/astr161/lect/history/newton3laws.html

Newton's Three Laws
of Motion

--------------------------------------------------------------------------------

Let us begin our explanation of how Newton changed our understanding of the Universe by enumerating his Three Laws of Motion.

Newton's First Law of Motion:
I. Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it.

This we recognize as essentially Galileo's concept of inertia, and this is often termed simply the "Law of Inertia".

Newton's Second Law of Motion:
II. The relationship between an object's mass m, its acceleration a, and the applied force F is F = ma. Acceleration and force are vectors (as indicated by their symbols being displayed in slant bold font); in this law the direction of the force vector is the same as the direction of the acceleration vector.

This is the most powerful of Newton's three Laws, because it allows quantitative calculations of dynamics: how do velocities change when forces are applied. Notice the fundamental difference between Newton's 2nd Law and the dynamics of Aristotle: according to Newton, a force causes only a change in velocity (an acceleration); it does not maintain the velocity as Aristotle held.

This is sometimes summarized by saying that under Newton, F = ma, but under Aristotle F = mv, where v is the velocity. Thus, according to Aristotle there is only a velocity if there is a force, but according to Newton an object with a certain velocity maintains that velocity unless a force acts on it to cause an acceleration (that is, a change in the velocity). As we have noted earlier in conjunction with the discussion of Galileo, Aristotle's view seems to be more in accord with common sense, but that is because of a failure to appreciate the role played by frictional forces. Once account is taken of all forces acting in a given situation it is the dynamics of Galileo and Newton, not of Aristotle, that are found to be in accord with the observations.

Newton's Third Law of Motion:
III. For every action there is an equal and opposite reaction.

This law is exemplified by what happens if we step off a boat onto the bank of a lake: as we move in the direction of the shore, the boat tends to move in the opposite direction (leaving us facedown in the water, if we aren't careful!).




Notice that Newton's 3 laws of motion deal with momentum, momentum transfer, and acceleration. NO ENERGY RELATIONSHIPS.

Prove this wrong Vapodog and Hotcore.
tu2


_____________________________________________________


A 9mm may expand to a larger diameter, but a 45 ain't going to shrink

Men occasionally stumble over the truth, but most of them pick themselves up and hurry off as if nothing had happened.
- Winston Churchill
 
Posts: 5077 | Location: USA | Registered: 11 March 2005Reply With Quote
One of Us
Picture of someoldguy
posted Hide Post
quote:
Just to throw a spanner in the works:- I am not sure of the momentum and energy figures, but 567 grains at 240 fps is just as deadly as any of the above, provided it is placed properly through heart and both lungs, and as long as the broadhead up front is razor sharp!


Glad you brought that up.
Here's what I mean when I talk about penetrating surface area. ClassicAl points out that an arrow is 3/8" in diameter. That's undoubtedly at the shaft of the arrow. The penetrating surface area involves the blades, or the point, of the arrow, which is substantially smaller than the shaft diameter. Since arrows obviously maintain a trajectory without tumbling, deforming, or losing mass, as compared with some bullets, then their penetration potential would be very high, when coupled with a high enough momentum.
(I'm not going to mention energy vs. resisting force because I get into trouble when I talk about that. Big Grin )


_________________________

Glenn

 
Posts: 942 | Location: Alabama | Registered: 16 July 2007Reply With Quote
one of us
posted Hide Post
I dunno how else to explain it better than I did before. Energy is the ABILITY to do work and the equation for it squares the velocity. Thus, a faster moving, light weight object will have more energy.
Momentum, being the MASS (NOT WEIGHT) of an object, is the ability of an object to maintain it's path of travel. Read the descriptions of Newton's Laws of Motion above. Good grief!!! The concept is bonehead simple. I don't see anywhere on this thread where it was said or implied momentum superceded energy. The two are intertwined and you can't have one without some of the other.
Bear in Fairbanks


Unless you're the lead dog, the scenery never changes.

I never thought that I'd live to see a President worse than Jimmy Carter. Well, I have.

Gun control means using two hands.

 
Posts: 1544 | Location: Fairbanks, Ak., USA | Registered: 16 March 2002Reply With Quote
one of us
posted Hide Post
quote:
Originally posted by jwp475:
Notice that Newton's 3 laws of motion deal with momentum, momentum transfer, and acceleration. NO ENERGY RELATIONSHIPS.

Prove this wrong Vapodog and Hotcore.
tu2
I'm not sure "Why?" you would think either of us would desire to go up against Newton's Laws.

However, the 3rd Law simply deals with "equal Energy being expended in opposite directions", nothing complicated about it. I'm also not sure "Why?" you are attempting to complicate it with "momentum, momentum transfer, and acceleration', when that is unnecessary to understanding the 3rd Law. bewildered

But the good news is - I DO NOT care and have no desire to argue. tu2
 
Posts: 9920 | Location: Carolinas, USA | Registered: 22 April 2001Reply With Quote
One of Us
Picture of vapodog
posted Hide Post
quote:
Originally posted by Hot Core:
But the good news is - I DO NOT care and have no desire to argue. tu2

It might be interesting if anyone had followed through as I asked and posted their minimum requirement for "momentum" for their choice of cartridge for hunting.....

So if one likes momentum over energy.....great....post your minimum requirements.....seems some just can't read! Hard to argue when folks are just plain unwilling to take a stand.


///////////////////////////////////////////////////////////////////////////
"Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery."
Winston Churchill
 
Posts: 28849 | Location: western Nebraska | Registered: 27 May 2003Reply With Quote
  Powered by Social Strata Page 1 2 3 4 5 6 7 8  
 

Accuratereloading.com    The Accurate Reloading Forums    THE ACCURATE RELOADING.COM FORUMS  Hop To Forum Categories  Rifles  Hop To Forums  Medium Bore Rifles    For you folks favoring momentum over energy...

Copyright December 1997-2023 Accuratereloading.com


Visit our on-line store for AR Memorabilia