Pass-through, is it needed?

[enewman]

Imho.

There is a midpoint/sweetspot where an arrow gets too heavy and slows down too much so that it starts to lose K.E.

But a heavier arrow (say 450gr) shooting 275fps (75.6 K.E.) is still better than a light arrow (say 350gr) shooting 312fps (75.7 K.E.). Because of momentum, imo. Harder to stop something "heavy".

Simple test would be to shoot the above two scenarios into the same object and see which one pokes out!

I'm in no way smart so mho really ain't worth much, lol. And I may or may not be drinking already!

For a compound I have tested to a 1500gr. no loss in KE

[Landrover]

you need to understand kinetic energy better, the kinetic energy of an arrow is less than most standard velocity .22 lr rounds,,, it is blood loss from cutting that kills with an arrow not ke, never was and never will be... and the energy to push an arrow through is momentum not ke,,,, ke has little to no killing effect with an arrow,,,

and pass throughs are far better than not,,, blood trails are most often better on the opposite side than entrance since most of us do not shoot level , instead we try to shoot from elevated as much as possible, and the lower hole is the one most blood pours out of,,, also an animal with an arrow still stuck in it tends to run much farther than one that had it pass through,,,,

Agreed, nothing debatable but always interesting to listen to others hypothesis.

The last few years (5 or so) I went into the cup of Ashby kool-aid. I built arrows for pass-throughs. What I got was consistently no blood trails. I have climbed out of that cup. got deep into physics. With my study of Physics, I have found that sometimes years back we stopped listening to the old-timers and we got into saying momentum is what does the killing. This is not what physics tells us. So, I have really been looking at how we can get the archery world back on track.

One thing I'm leaving out is mass. we must not forget about mass.

I can only disagree based on MY setup concerning blood trails. From little Texas whitetails to cape buff, moose, bison, giraffe my experience has been amazing. Look forward to seeing your results. Are you having it peered reviewed?

What matters is the work that an arrow/broadhead performs. Just because an arrow completely passes though the animal, it doesn't mean it hasn't done adequate work to kill the animal. I agree that, with fixed blade broadheads, you sometimes don't get great blood trails. That being said, if correctly placed, it won't matter. On marginal hits, expandables may be a better choice, because they do more work (tissue damage) than a fixed head. The problem with expandable is that you get more marginal hits due to lack of penetration when hitting solid bone. Shot placement is by far the most important factor, and everything else is making up for poor shot placement.

Definitely mechanicals don't deaux well on bone.....again non debatable on multiple levels. Not sure what mechanicals folks are considering well made but blood trailing is not an issue....not even a concern.

Same here, no issue with the Slick Tricks. Mechanical is a band-aid for a poorly tuned bow or bad Indian.

LOL........thank God the number of bad Indians is decreasing as the better shops are really working with customers.

So I understand the "momentum is not work" statement from a physics standpoint, but doesn't the bold part prove that momentum is a pretty important part of the recipe?

The one thing I consistently take away from a heavier arrow/fixed blade setup is that you don't have to worry so much when shooting the "v" with thin blades on expandables.

I'm not a kool-aid drinker from any camp though... I don't bite on the 600gr setups with 20% FOC or the 350gr setups with expandables that are constantly hanging halfway out of a 150lb whitetails ribcage. I like a an arrow with a little more FOC and somewhere around 450gr, and I really prefer a true COC broadhead. I know for a fact that with a sharp head that zips through critters, you get way less reaction to the shot.

Good paper though E...I always appreciate your posts!

Just the idea that 450 has become normalized is a beautiful advancement in the world of bowhunting! I remember OVERDRAWS, thus if KE was the KEY we all would be using that system from the 80's.

I’m interested to see this test. I thought physics said the heavier object would be harder to stop, but it’s been a minute since I picked up a physics book, thank God.


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You nailed it and not much need for a book to think thru that. Would someone rather get hit by a ping-pong ball thrown by a MLB pitcher or a golf ball? Momentum continues down range at relatively the same force over a known distance. KE fades as it goes down range at the same known distance. Both have been proven long ago. But as always, I am open to reviewing new hypothesis and new peered reviewed sources. Full disclosure, I have 100% drank the Dr. Ashby Foundation kool-aid. Lots of folks with really promising hypothesis have challenged the findings but none have beat them. Most look for middle ground, which is fair enough. But positive attempts to discount the findings are non existent today. Debating the definitions of Kinectic energy and Momentum is a red herring from my standpoint. It is about what the total setup can do on bone and tissue of a big game animal. State based and global governments (always last to jump on board) are altering guidelines based on Dr. Ashby Foundation reports. Yes, also TPWD is adopting the guidelines as wounding loss in the state is a real concern......especially with the suburban mom! A total arrow system with a proper designed (structural integrity) broadhead on a tuned BOW is imperative, just no way around that critical aspect.

[enewman]

Agreed, nothing debatable but always interesting to listen to others hypothesis.

I can only disagree based on MY setup concerning blood trails. From little Texas whitetails to cape buff, moose, bison, giraffe my experience has been amazing. Look forward to seeing your results. Are you having it peer reviewed?

Definitely mechanicals don't deaux well on bone.....again non debatable on multiple levels. Not sure what mechanicals folks are considering well made but blood trailing is not an issue....not even a concern.

LOL........thank God the number of bad Indians is decreasing as the better shops are really working with customers.

Just the idea that 450 has become normalized is a beautiful advancement in the world of bowhunting! I remember OVERDRAWS, thus if KE was the KEY we all would be using that system from the 80's.

You nailed it and not much need for a book to think thru that. Would someone rather get hit by a ping-pong ball thrown by a MLB pitcher or a golf ball? Momentum continues down range at relatively the same force over a known distance. KE fades as it goes down range at the same known distance. Both have been proven long ago. But as always, I am open to reviewing new hypothesis and new peered reviewed sources. Full disclosure, I have 100% drank the Dr. Ashby Foundation kool-aid. Lots of folks with really promising hypothesis have challenged the findings but none have beat them. Most look for middle ground, which is fair enough. But positive attempts to discount the findings are non existent today. Debating the definitions of Kinectic energy and Momentum is a red herring from my standpoint. It is about what the total setup can do on bone and tissue of a big game animal. State based and global governments (always last to jump on board) are altering guidelines based on Dr. Ashby Foundation reports. Yes, also TPWD is adopting the guidelines as wounding loss in the state is a real concern......especially with the suburban mom! A total arrow system with a proper designed (structural integrity) broadhead on a tuned BOW is imperative, just no way around that critical aspect.

explain that?

just going to make up numbers/

at bow 500gr 300fps ke=99.9 momentum is .666. downrange 280fps KE is 87.02 momentum .622 . Now that is a difference in KE of 13.78% and a difference of 6.83%. it should be behalf. 13.78/2 is 6.89. so close enough.

That means they are losing at the same rate. KE is not losing faster.
Now let me explain the half so we don't get confused. it comes from how we calculate KE and momentum. KE=.5*m*v^2/225218. Momentum is m*v. so because velocity is squared is the reason we see a 13.78 difference to the 6.83. but the rate of loss is all based on velocity. It's the same. it would be physically impossible to lose at a different rate.

If you understand physics, KE is the factor with mass. if you don't understand. all I can do is tell you to please research and study. might be helpful to go find a physics professor.

As far as Ashby. his findings are good. his tests are beyond horrific. nothing he did is quantifiable. it's easy to show.

I hope that someone in the tpwd gets their head out. Ashby's studies are only good for low-energy setups and at 20 yards. That is it.

Again debating KE and momentum is a red hearing in your book. It should be. As soon as momentum is talked about. People that talk about momentum have no clue about physics. It's truly sad. Our education department has failed us.

also, why would be using overdraw for KE. that seems foolish? If we are shooting the same bow KE will increase as mass is added.

thank you.

by the way you sound like a guy I know (ROB)

peer review. Yes, I am looking into this, but since you like talking about Ashby. His hasn't been peer review. It has been talked about being done. now it may have but it would have been in the last couple of years, and no information has been posted about it. if it had been I'm very sure it would be a high light on their page.

[quackadikt]

Don’t mean to put words in Landrover’s mouth, but he might mean that as you decrease mass to increase speed and KE, you loose speed and ke faster down range(because of the lighter arrow)?

Like all things in life, there’s a happy medium and a point of diminishing return. That MLB pitcher example is perfect. A ping pong ball is going to hit the dirt before it makes it to the plate because it looses all its KE/M before it gets there. A bowling ball will do the same because it’s too far to the other end of the spectrum and it looses speed, thus KE(I think that’s technically correct?). A baseball is a happy medium.


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[enewman]

Don’t mean to put words in Landrover’s mouth, but he might mean that as you decrease mass to increase speed and KE, you loose speed and ke faster down range(because of the lighter arrow)?

Like all things in life, there’s a happy medium and a point of diminishing return. That MLB pitcher example is perfect. A ping pong ball is going to hit the dirt before it makes it to the plate because it looses all its KE/M before it gets there. A bowling ball will do the same because it’s too far to the other end of the spectrum and it looses speed, thus KE(I think that’s technically correct?). A baseball is a happy medium.


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if so this yes he is correct. I looked at it as one arrow, not two. thank you.

[ldsalmon]

explain that?

just going to make up numbers/

at bow 500gr 300fps ke=99.9 momentum is .666. downrange 280fps KE is 87.02 momentum .622 . Now that is a difference in KE of 13.78% and a difference of 6.83%. it should be behalf. 13.78/2 is 6.89. so close enough.

That means they are losing at the same rate. KE is not losing faster.
Now let me explain the half so we don't get confused. it comes from how we calculate KE and momentum. KE=.5*m*v^2/225218. Momentum is m*v. so because velocity is squared is the reason we see a 13.78 difference to the 6.83. but the rate of loss is all based on velocity. It's the same. it would be physically impossible to lose at a different rate.

If you understand physics, KE is the factor with mass. if you don't understand. all I can do is tell you to please research and study. might be helpful to go find a physics professor.

As far as Ashby. his findings are good. his tests are beyond horrific. nothing he did is quantifiable. it's easy to show.

I hope that someone in the tpwd gets their head out. Ashby's studies are only good for low-energy setups and at 20 yards. That is it.

Again debating KE and momentum is a red hearing in your book. It should be. As soon as momentum is talked about. People that talk about momentum have no clue about physics. It's truly sad. Our education department has failed us.

also, why would be using overdraw for KE. that seems foolish? If we are shooting the same bow KE will increase as mass is added.

thank you.

by the way you sound like a guy I know (ROB)

peer review. Yes, I am looking into this, but since you like talking about Ashby. His hasn't been peer review. It has been talked about being done. now it may have but it would have been in the last couple of years, and no information has been posted about it. if it had been I'm very sure it would be a high light on their page.

How are you replicating the targets movement during your tests? Or are you? Maybe the deer you shoot don't move as the arrow passes through them.

I see that you keep reminding everyone that they need to understand physics but you are oversimplifying the interaction between the two bodies (arrow / target). You have omitted any discussion about collisions and the duration in which the interactions occur. If your target is stationary, and remains that way, there is no contribution of KE or initial momentum. I'm no physicist and am not discrediting what you are trying to say, but you sure seem to be neglecting a large portion of what all happens when an arrow is shot into a live animal, and the resulting lethality.

[quackadikt]

I think Enewman is making the point that if momentum is a constant, higher KE will penetrate more.

We all know that the lighter object can start faster but it also slows faster. This is why speed is such a big factor in steel shot compared to lead.


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[enewman]

Don’t mean to put words in Landrover’s mouth, but he might mean that as you decrease mass to increase speed and KE, you loose speed and ke faster down range(because of the lighter arrow)?

Like all things in life, there’s a happy medium and a point of diminishing return. That MLB pitcher example is perfect. A ping pong ball is going to hit the dirt before it makes it to the plate because it looses all its KE/M before it gets there. A bowling ball will do the same because it’s too far to the other end of the spectrum and it looses speed, thus KE(I think that’s technically correct?). A baseball is a happy medium.


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I like comparing objects. let's look at the ping pong ball vs baseball.
ping pong is 41.7gr. and the baseball is 2237.7gr. so at 90mph (130fps) that baseball has 84ft-lbs. so to compare the two we need to match KE. which means the ping pong ball would be traveling at 952fps. now let's match momentum. baseball at 130fps is 1.29 slug-ft/s that means the ping pong is traveling at just over 7000fps. that is 4484ft-lbs. what does that mean? if the ping pong ball is matched in momentum it will probably kill you where the baseball is just going to hurt like hell. haha crazy isn't it.

by the way, I just showed physics. two unequal objects but equal momentum the lighter object will have the highest KE and will do more work.

so which one matters KE or momentum. KE with out a doubt. pure physics

[enewman]

How are you replicating the targets movement during your tests? Or are you? Maybe the deer you shoot don't move as the arrow passes through them.

I see that you keep reminding everyone that they need to understand physics but you are oversimplifying the interaction between the two bodies (arrow / target). You have omitted any discussion about collisions and the duration in which the interactions occur. If your target is stationary, and remains that way, there is no contribution of KE or initial momentum. I'm no physicist and am not discrediting what you are trying to say, but you sure seem to be neglecting a large portion of what all happens when an arrow is shot into a live animal, and the resulting lethality.

my test is a physics test. it is not on animals in the first part of the test. the first part is to teach people that KE is what is doing the work and get people to understand momentum is not. then I will start the second test. this one will introduce impulse. somewhere I will also show why we get gain as we add mass and show that some manufactures are getting to a point that we are seeing almost no gain increasing mass. bows are getting very efficient now.

[TxBowHntr]

I am by no means a physics expert, so please correct me if I am wrong. I am not understanding why KE is important but not momentum. I thought KE is the amount of energy carried by the arrow. Momentum is a vector, ie, the KE exerted in a specific direction. Is this not the case?

[enewman]

I am by no means a physics expert, so please correct me if I am wrong. I am not understanding why KE is important but not momentum. I thought KE is the amount of energy carried by the arrow. Momentum is a vector, ie, the KE exerted in a specific direction. Is this not the case?

Both are important. As long as the arrow is moving, it has both. It will have both till the arrow stops. Ke energy is what is doing the work do to force and displacement. Momentum is how hard to stop or change the direction of the arrow. That is impulse.

The more KE, the more penetration. The more momentum, the harder it is to stop.

I'm far from a physics expert myself. I have only been studying where it pertains to archery for about two years. I have a professor that helps me.

[enewman]

I am by no means a physics expert, so please correct me if I am wrong. I am not understanding why KE is important but not momentum. I thought KE is the amount of energy carried by the arrow. Momentum is a vector, ie, the KE exerted in a specific direction. Is this not the case?

Here is a good video.

https://www.bing.com/videos/search?q=is%20kinetic%20energy%20work&qpvt=is%20kinetic%20energy%20work&view=detail&mid=B03969DC4B7A7BD678B5B03969DC4B7A7BD678B5&&FORM=VRDGAR&ru=%2Fvideos%2Fsearch%3Fq%3Dis%2Bkinetic%2Benergy%2Bwork%26qpvt%3Dis%2Bkinetic%2Benergy%2Bwork%26FORM%3DVDRE

[TxBowHntr]

Both are important. As long as the arrow is moving, it has both. It will have both till the arrow stops. Ke energy is what is doing the work do to force and displacement. Momentum is how hard to stop or change the direction of the arrow. That is impulse.

The more KE, the more penetration. The more momentum, the harder it is to stop.

I'm far from a physics expert myself. I have only been studying where it pertains to archery for about two years. I have a professor that helps me.

I don't understand how KE means more penetration. KE needs to be traveling in a specific direction with all of its mass traveling inline in order to mean more penetration. This is why a well tuned bow/arrow is important. Just having the KE doesn't necessarily equate to penetration. It needs to be exerted in a specific vector which would turn it into momentum.

Your quote above that more momentum means harder to stop, isn't an arrow that is harder to stop mean more penetration?

I am not trying to be argumentative, I really would like to learn the difference in KE and momentum and how they relate to archery. Are there any articles written that explain KE and momentum that you could reference? I'd like to read up on it.

[TxBowHntr]

Here is a good video.
https://www.bing.com/videos/search?q...%26FORM%3DVDRE

Thanks, I'll check it out

[enewman]

Thanks, I'll check it out

here is another one.

https://www.bing.com/videos/search?q=is+kinetic+energy+work&ru=%2fvideos%2fsearch%3fq%3dis%2bkinetic%2benergy%2bwork%26qpvt%3dis%2bkinetic%2benergy%2bwork%26FORM%3dVDRE&qpvt=is+kinetic+energy+work&view=detail&mid=4FCDF00B90BAB41C890C4FCDF00B90BAB41C890C&rvsmid=B03969DC4B7A7BD678B5B03969DC4B7A7BD678B5&FORM=VDMCNR