TheArcheryProgram

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Thanks TheArcheryProgram!
I am glad this didn't degenerate into something ugly as I enjoyed the thread and thinking about the issues.

It would be real interesting to chrono various arrows at a number of ranges and do the math to see what is really happening out at longer hunting distances with hunting set-ups.

Anyone want to?

Greg

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What do you need to do all the work for? Thats why I wrote this friggin program!

I just ran the data of SikYou's measured data and here is my guess on his fletch being he didn't list what he used.

My program shows less than 1 f/s difference from his measured results when I used a 3&quot; vane for fletch.......SiskYou, what type of fletches did you use? I am curious!

I also have a question on the 300 arrow. How did you get it to 377 grains? I used a 28&quot; length on the 200's with 18 grains for the fletch and it comes right for weight, when I select the 300's I had to add an additional 20 grains for the same length arrow to get it up to 377 grains.....did you use a heavier tip, or larger fletches? Again I am just curious.....not busting balls!

Happy Shooting!




&gt;&gt;&gt;------Tony Virnoche------&gt;&gt;&gt;
&gt;&gt;&gt;---The Archery Program---&gt;&gt;&gt;

Edited by - thearcheryprogram on 08/14/2002 20:25:40

TFOX

Here we go again.


First of all let me say that it seems that some are confusing momentum as speed(as I once did)but it is a combination of speed and weight and ke.

Weight of arrow divided by 7000 multiplied by speed of arrow will give the momentum of an arrow.The actuall bone crushing number that we look for.



The mechanical definition for ke is this.

ke:The motion of a body may be one of pure translation,pure rotation,or a combination of rotation and translation.(By translation is meant motion in which every line in the body remains parallel to it's original position throughout the motion,that is,no rotation is associated with the motion of the body.)

IMO this says to me that ke gives us a value to how well an arrow remains traveling parralel and forward without the backend trying to pass the front.This is a very critical number for penetration because the higher the ke the straighter the arrow will remain when entering an animal.Of course with an arrow foc can play with this equation also.Get too light in the front and all the ke is used up at first release to try and get the arrow going straight.



Here is where I differ than some.I think speed is also somewhat important because it gives the arrow the ability to fight off friction.Sort of like pushing a block of steel across the table.Really hard to get it started but once it has started,it gets easier to push the faster it goes.


Arthur,I see you have gone back to the percentages of speed lost.I can't disagree completely but the arrow is what will make the final determination for that.


I just showed these numbers on the bowhunting forum but I will repost them here.

These numbers are from my bow

Easton 2214

grains fps distance ke
450 gr 240 fps 0 yards 57.5 ke
same 217 fps 50 yards 47.3 ke


ACC 3-39
grains fps distance ke
388 gr 256 fps 0 yards 56.7 ke
same 233 fps 50 yards 47.2 ke



Now if you look closely you will see at 50 yards there is only a difference in ke of .1 ft/lb.

At 55 yards they are identical and after that the ACC has more ke.At 30 yards there is only a diifference of .3 ft/lb.



Speed is always better with the ACC and ke is not really relevant between these 2.


I used these arrows because they are perfectly spined for my setup and ultimately that is the most important thing for figuring penetration.As well as a good broadhead.



I do believe that there are way too many factors for one magical number to give you the value needed to pass thru an animal.The variables are endless.

Although,I believe ke is a good place to start.

Straightarrow

<BLOCKQUOTE id=quote<font size=1 face='Verdana, Arial, Helvetica' id=quote>quote:<hr height=1 noshade id=quote>Personally, I think far too many people put way too much importance on speed and flat trajectory over typical hunting distances when they should be more concerned about getting their arrow to the animal with as oomph as possible. <hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face='Verdana, Arial, Helvetica' size=2 id=quote>

Arthur, your point is probably very pertinent for someone shooting a borderline level of KE. I personally am not a speed merchant, but once I'm shooting enought KE that my arrow is passing through a deer inside of 30 yards, as long as I maintain accuracy, extra speed will enable me to get away with a greater amount of yardage misjudgement. Even if I only gain an inch or two less drop, it's better served than just burying my broadhead deeper into the dirt. In my opinion, judging yardard incorrectly is a major reason many animals are not killed, and most hunters would be better served by a little more speed, as long as they are able to still shoot accurately at whatever that speed is.

Arthur P

TFOX. I always go back to speed lost because it shows how well heavy arrows retain speed over distance. Even though they don't get there as quick as light arrows, they retain a greater portion of their speed. Since they retain more speed, they retain more energy downrange. And, since they are slower, they also meet less resistance to penetration than the fast, light ones.

I don't disagree with your numbers, but you're comparing arrows with only 62 grains difference in weight. I'm comparing arrows weighing 350 grains different.

Light, fast arrows lose speed and carry less energy to the target than slow, heavy arrows and meet with greater resistance to penetration. For someone that's shooting enough bow to blow a toilet plunger thru a Caddy, this part of the penetration equation is definitely splitting hairs. But StraightArrow's point is well made. Not just everyone shoots a he-man bow. For someone that's shooting a low energy setup, a proportionally heavy arrow could mean the difference between a superificial wound and a short blood trail.

We all strive for a well placed arrow, but stuff happens. It's happened to me, when I got a bad release (sweat soaked shooting glove hung up on the string) and hit a hog in the neck with a fishtailing arrow at around 20 yards. But I was fortunate to be shooting a tough broadhead and enough arrow weight to bail me out of what could have been a bad situation. KE was all of 45 ft lbs out of that old recurve but, even with the tail wagging, that 650 grain arrow had just enough juice to bust thru a vertebra in the pig's neck and dropped it in it's tracks.

Would a 400 grain arrow have done the same thing out of that bow? I honestly don't know and I don't ever want to find out.


Edited by - Arthur P on 08/14/2002 22:14:37

Arthur P

Straigtarrow, I disagree that misjudged yardage is that big a reason that animals are wounded and lost. Not that it doesn't happen but with the reliable lazer rangefinders we've got these days, it shouldn't be that big a proportion of the total. In my opinion, lost animals are due more to people shooting beyond their skill level, being over-bowed (because they think they need that speed and flat trajectory), not enough preseason shooting practice to learn how to control that all that speed under hunting conditions, poor tracking skills and, worst of all, not caring enough to follow up a shot and do all they can to find that animal.

TFOX

Arthur,

It is really hard to get arrows that are correctly spined to have 350 grains difference in weight.

It wouldn't even be feasable to me to even try to do so on any game in North America.


I also think that speed does not cover up the lack of yardage judging.It is way overated IMO.
When a sight is set for a particular yardage the MISS DIFFERENCE in arrows shot up to 20 fps difference is very small.About 1/2&quot; at 40 yards when misjudging by 3 yards.That is only 1&quot; at 40 fps.This is ,of course,from the same bow and same poundage.


I do,on the otherhand, like the arrow getting to the target a little faster for some of the longer shots that I may encounter.


Carbon arrows retain more downrange ke due to the smaller diameter.Smaller is better.<img src=icon_smile_big.gif border=0 align=middle>

IndyHunter

Okay lets see if I have this right. The momentum of the vortex is equilaterally proportionate to the apex of the vortex's axis, assuming the kenetic energy is equal to or less than the projectiles warp factor speed at said range. Yep, I think i've got it!
The only question left to be answered is once the arrow penetrates the animal, will the arrow lose more KE in mud, sand, loose gravel, or regular ole dirt?
Just kidding around, this thread has made for some good reading.

-Man who fight with wife all day get no piece at night-

Arthur P

TFOX. No problem at all for ape armed ol' me to get a 350 grain arrow and a 700 grainer spined correctly for the same bow. 70 pound hard cam bow, 34&quot; 2419 with a 145 gn tip and 5&quot; feathers (could go about 20 gns heavier with 5&quot; vanes) and then slap an overdraw on the same bow for a short carbon. Not that I would want to do the latter at my draw length, but I could. <img src=icon_smile_wink.gif border=0 align=middle>

Now, about carbon arrows carrying more energy downrange... If two arrows were the same weight and started off flying the same speed, you would be correct to say the smaller diameter carbon arrow would encounter less wind resistance, retain more speed and deliver more KE downrange than the larger diameter arrow. However, your own numbers show ACC's losing almost exactly the same amount of speed and energy as that larger diameter 2214 and both arrows arriving at 50 yards with practically identical energy levels. Not more energy for the carbon. Identical energy.

ACC's have a smaller diameter but are flying with more speed, and air resistance increases in proportion to speed squared. Odd though it may seem, the ACC's extra speed increased the air resistance exactly enough to offset the smaller diameter in your examples.

I don't know how far those longer shots are that you are confronted with, but I'll assume they're less than 50 yards. Difference in time of flight would less than 4/100ths of a second with only a 16 fps difference in speed between the ACC and the 2214 at 50 yards. Within 30, the difference would be so slight as to be totally meaningless (as if .04 second is really meaningful anywhere but the races). To get a real difference in time of flight, you'd have to do what I do and really slow down speed by bumping arrow weight way up.

I hope nobody is getting the idea that I think everyone should shoot 10-12 grains per pound of draw weight like I do. I'm simply trying to prove that there is NO practical benefit to the vast majority of bowhunters to warrant shooting 5 grains per pound and stressing about chronograph numbers. In my opinion, they would be far better off to settle in on a moderate weight arrow around 7 grains per pound, tune it in, learn to shoot it accurately and totally forget they ever heard of IBO speed ratings or a gizmo called a chronograph.

Edited by - Arthur P on 08/15/2002 00:41:15

Edited by - Arthur P on 08/15/2002 00:43:04

Straightarrow

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Straigtarrow, I disagree that misjudged yardage is that big a reason that animals are wounded and lost. Not that it doesn't happen but with the reliable lazer rangefinders we've got these days, it shouldn't be that big a proportion of the total. In my opinion, lost animals are due more to people shooting beyond their skill level, being over-bowed (because they think they need that speed and flat trajectory), not enough preseason shooting practice to learn how to control that all that speed under hunting conditions, poor tracking skills and, worst of all, not caring enough to follow up a shot and do all they can to find that animal.
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Arthur,

I agree that yardage misjudgement is not the biggest reason for missed deer and that many other factors can cause problems, but I don't know a single hunter with a rangefinder (I know lots of hunters) and I can't count the number of times a hunter told me something like, &quot;I thought he was at 20 and it turned out to be 32 yards and I just nicked him in the belly&quot;.

In my opinion, if you have a hunter who has developed their shooting skills and are shooting a late model compound with at least a 55 lb draw, most would be better off with a bit more speed, even if the benefit is not very large. The ones who don't practice, can't be bother to learn tracking, and put as much effort into preparation as they do for thanksgiving dinner, are probably beyond our help. I guess it comes down to evaluating one's skill level and the energy produced by their set-up. Many of us are going to benefit from the extra speed more than the extra penetration.

Arthur P

Straightarrow, yeah, I've heard that sob story about 'thought he was 20 but he was standing at 30.' For Pete's sake, anybody that can't tell the difference between 20 and 30 yards darned well better go out and buy a rangefinder or spend every weekend on a 3D course somewhere and learn how to judge yardage. Quite frankly, I bet most of those stories would be more truthfully told as 'thought he was at 40 but he was at 50.' Or 'I didn't see a single deer all weekend but want you to think I at least shot an arrow.'

We're simply going to have to agree to disagree on any benefit for most people to have all that speed. My opinion is that excess speed, anything much over 250 fps, causes too many tuning problems and makes bow setups too critical of shooting errors to be a serious hunting tool for most people. Heck, I've been shooting a bow for nearly half a century and I'm not good enough to handle that kind of gear in the woods! I guarantee you that the vast majority of bowhunters do not have enough skill and experience to shoot blazing speed and be consistently successful with it. And that leads directly to increased chances for bad shot placement, poor penetration and wounded animals.

I'm not talking the guys that live at the range and actually ARE regulars on a 3D course or field archery course and are shooting 3-4 indoor leagues all year long. Those guys certainly don't need any advice from ME.

Problem is that those guys are a very, very small minority of the fellers in the woods during bow season.


Edited by - Arthur P on 08/15/2002 08:25:14