Light arrows bad choice for hunting
12-31-2002 | 10:00 AM
#1
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From: Murrysville PA USA
Light arrows bad choice for hunting
For each grain per pound draw decrease in arrow weight the penetration decreases by 9% while the effective range of a bow increases by one and a quarter yards.
For hunting I think that this means that one needs to use 9 grains per pound - the AMO standard - to be an ethical hunter. Only a fool would knowingly give up 9% in penetration for a 1.25 yard increase in effective range.
The numbers are based on "The Archery Program" where I looked at the momentum and KE at 30 yards - if the advantage of light arrows is long range shooting, then it does not make sense to look at closer distances.
At 30 yards, a 630 grain arrow has 35% more momentum and 26% more kinetic energy than does a 350 grain arrow. Momentum is more important for penetration, so each grain per pound of draw weight leads to almost a 9% increase in penetration.
At 30 yards, a 5 yard mis-estimation of distance leads to a 5 inch error with the heavy arrow. At 35 yards, a 5 yard mis-estimation of distance leads to a 5 inch error with the light arrow. A 5 inch error takes the arrow out of the "8 inch kill zone" so defines the effective range of the arrow. So for each grain per pound, there was a 1.25 yard increase in effective range.
The heavy arrow slows down less in flight because it is heavier and because the drag on it is less than on a faster moving arrow. The heavier arrow starts out with 10% more KE because the bow is more efficient at higher arrow weights.
Yes, yes, I know -> you already get full pass throughs on GOOD hits. Personally, I'm not good enough at this to assure myself that I will never have a bad hit. And I would suggest that one could use a blade with a greater cutting radius or more blades if one is concerned about leaving the extra energy of the heavier arrow in the bank on the far side of the deer.
And, the light arrow is much harder to tune for broadheads leading, in part, to the relative popularity of mechanicals. Light arrows being ironic in that they rob the arrow of down range KE plus encourage the use of a broadhead which requires MORE KE to make it function. All for a TINY increase in effective range.
Who is at fault? The bow manufacturers who have based their marketing on speed, speed, speed.
I want to also blame the archery magazines, but let me wait until I read a few more issues - I've been out of hunting for a few years, in the father business.
The above is based on a 70 pound bow, 30 inch draw, 31 inch arrow, 5 inch fletch, 7.5 inch brace height.
beprepn
Edited by - beprepn on 12/31/2002 16:16:31
Edited by - beprepn on 01/03/2003 18:46:56
For hunting I think that this means that one needs to use 9 grains per pound - the AMO standard - to be an ethical hunter. Only a fool would knowingly give up 9% in penetration for a 1.25 yard increase in effective range.
The numbers are based on "The Archery Program" where I looked at the momentum and KE at 30 yards - if the advantage of light arrows is long range shooting, then it does not make sense to look at closer distances.
At 30 yards, a 630 grain arrow has 35% more momentum and 26% more kinetic energy than does a 350 grain arrow. Momentum is more important for penetration, so each grain per pound of draw weight leads to almost a 9% increase in penetration.
At 30 yards, a 5 yard mis-estimation of distance leads to a 5 inch error with the heavy arrow. At 35 yards, a 5 yard mis-estimation of distance leads to a 5 inch error with the light arrow. A 5 inch error takes the arrow out of the "8 inch kill zone" so defines the effective range of the arrow. So for each grain per pound, there was a 1.25 yard increase in effective range.
The heavy arrow slows down less in flight because it is heavier and because the drag on it is less than on a faster moving arrow. The heavier arrow starts out with 10% more KE because the bow is more efficient at higher arrow weights.
Yes, yes, I know -> you already get full pass throughs on GOOD hits. Personally, I'm not good enough at this to assure myself that I will never have a bad hit. And I would suggest that one could use a blade with a greater cutting radius or more blades if one is concerned about leaving the extra energy of the heavier arrow in the bank on the far side of the deer.
And, the light arrow is much harder to tune for broadheads leading, in part, to the relative popularity of mechanicals. Light arrows being ironic in that they rob the arrow of down range KE plus encourage the use of a broadhead which requires MORE KE to make it function. All for a TINY increase in effective range.
Who is at fault? The bow manufacturers who have based their marketing on speed, speed, speed.
I want to also blame the archery magazines, but let me wait until I read a few more issues - I've been out of hunting for a few years, in the father business.
The above is based on a 70 pound bow, 30 inch draw, 31 inch arrow, 5 inch fletch, 7.5 inch brace height.
beprepn
Edited by - beprepn on 12/31/2002 16:16:31
Edited by - beprepn on 01/03/2003 18:46:56
12-31-2002 | 10:49 AM
#5
Joined: Feb 2003
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From: Blissfield MI USA
RE: Light arrows bad choice for hunting
Well that is your opinion, and your welcome to it, but it is really just that, your opinion. There are many more factors that go into the penitration issue other than flat out Ke at a specific range.
And the grain/lb you decide to shoot really depends on your particular set up. 9 grn/ lb for me is way to heavy, but I don't have a real efficient bow and only draw 26 inches. The equivilant for my bow is -1.7 grns/lb.
Ke, really only measures the amount of knockdown power something has at a given range. Some other things that effect penitration are arrow dia., arrow stiffness, resistance of the target, and head type. My bow will actually get better penitration on a 3-d target with a lighter arrow than a heavier one. The heavier one hits the target harder, but does not really penitrate deeper.
You do make a good point and I mostly agree with you. Using an extremely light arrow may not be your best bet, but then neither would a real heavy arrow. You need to find what works best with your bow. A happy medium between decent speed and efficient Ke.
I will tell you this though, and it actaully agrees with your above statement. My bow likes a heavier arrow as far as the amount of energy it will devolop. I went to a shop and chronoed some different arrows at different draw weights and then came home and entered the data into the Archer Program. What I found is my Perfomance factor goes up with the heavier arrow. I only got 183 fps out of a 456 grn arrow at 42 lbs. But when I compared it to a 312 grn arrow moving at 214 fps the performance factor was way higher. Like 1.4 for the heavier arrow, vrs 1.2 something for the lighter arrow.
Keep in mind that does not mean the heavier the arrow, the better it will work. If you go to extremes in either direction performance will suffer. Just because a calculator or mathmatical equation says a heavier arrow will hit harder does not mean you will get that sort of performance out of your bow. You can get to a point were the arrow is too heavy for the bow to use it effectively and your performance will actually start to decrease. The ballistics formulas do not take into account for that. The only way to really know is shoot that weight of an arrow out of your bow and record the speed, then compare it with other arrows.
With that said, I feel confident that my bow with 30 some ft/lbs of KE at 20 yards will zip thru a deer with the right head, as long as I didn't hit the shoulder. To say that someone shooting a faster bow that gets 60lbs of KE with a 300 grn arrow can't do the same thing is a bit rediculous. I am not saying that the same arrow at 400 grns or so would not work better, but at 20 yards it probably does not matter much.
Those are my opinions on the subject anyway.
Paul
And the grain/lb you decide to shoot really depends on your particular set up. 9 grn/ lb for me is way to heavy, but I don't have a real efficient bow and only draw 26 inches. The equivilant for my bow is -1.7 grns/lb.
Ke, really only measures the amount of knockdown power something has at a given range. Some other things that effect penitration are arrow dia., arrow stiffness, resistance of the target, and head type. My bow will actually get better penitration on a 3-d target with a lighter arrow than a heavier one. The heavier one hits the target harder, but does not really penitrate deeper.
You do make a good point and I mostly agree with you. Using an extremely light arrow may not be your best bet, but then neither would a real heavy arrow. You need to find what works best with your bow. A happy medium between decent speed and efficient Ke.
I will tell you this though, and it actaully agrees with your above statement. My bow likes a heavier arrow as far as the amount of energy it will devolop. I went to a shop and chronoed some different arrows at different draw weights and then came home and entered the data into the Archer Program. What I found is my Perfomance factor goes up with the heavier arrow. I only got 183 fps out of a 456 grn arrow at 42 lbs. But when I compared it to a 312 grn arrow moving at 214 fps the performance factor was way higher. Like 1.4 for the heavier arrow, vrs 1.2 something for the lighter arrow.
Keep in mind that does not mean the heavier the arrow, the better it will work. If you go to extremes in either direction performance will suffer. Just because a calculator or mathmatical equation says a heavier arrow will hit harder does not mean you will get that sort of performance out of your bow. You can get to a point were the arrow is too heavy for the bow to use it effectively and your performance will actually start to decrease. The ballistics formulas do not take into account for that. The only way to really know is shoot that weight of an arrow out of your bow and record the speed, then compare it with other arrows.
With that said, I feel confident that my bow with 30 some ft/lbs of KE at 20 yards will zip thru a deer with the right head, as long as I didn't hit the shoulder. To say that someone shooting a faster bow that gets 60lbs of KE with a 300 grn arrow can't do the same thing is a bit rediculous. I am not saying that the same arrow at 400 grns or so would not work better, but at 20 yards it probably does not matter much.
Those are my opinions on the subject anyway.
Paul
12-31-2002 | 10:58 AM
#6
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From: Murrysville PA USA
RE: Light arrows bad choice for hunting
<BLOCKQUOTE id=quote<font size=1 face='Verdana, Arial, Helvetica' id=quote>quote:<hr height=1 noshade id=quote>
Thanks for the info beprepn. I guess I'll stick with my 700 grain arrow at 10 grains per pound.
P.S. I'm sure that you've opened a can of worms.
<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face='Verdana, Arial, Helvetica' size=2 id=quote>
Presumably 10 grains per pound would be even better!
I don't think there are any big holes in what I've said - in fact, this may have been the conventional wisdom 30 years ago.
I asumed that the bow got 11% more efficent at the higher arrow weight. I had bow reports from 1996 for 3 bows that gave 10.3 to 13.5% increase in efficiency when going from AMO to IBO arrow weights.
Thanks for the info beprepn. I guess I'll stick with my 700 grain arrow at 10 grains per pound.
P.S. I'm sure that you've opened a can of worms.
<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face='Verdana, Arial, Helvetica' size=2 id=quote>
Presumably 10 grains per pound would be even better!
I don't think there are any big holes in what I've said - in fact, this may have been the conventional wisdom 30 years ago.
I asumed that the bow got 11% more efficent at the higher arrow weight. I had bow reports from 1996 for 3 bows that gave 10.3 to 13.5% increase in efficiency when going from AMO to IBO arrow weights.
12-31-2002 | 11:22 AM
#8
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From: Murrysville PA USA
RE: Light arrows bad choice for hunting
<BLOCKQUOTE id=quote<font size=1 face='Verdana, Arial, Helvetica' id=quote>quote:<hr height=1 noshade id=quote>
...
I will tell you this though, and it actaully agrees with your above statement. My bow likes a heavier arrow as far as the amount of energy it will devolop. I went to a shop and chronoed some different arrows at different draw weights and then came home and entered the data into the Archer Program. What I found is my Perfomance factor goes up with the heavier arrow. I only got 183 fps out of a 456 grn arrow at 42 lbs. But when I compared it to a 312 grn arrow moving at 214 fps the performance factor was way higher. Like 1.4 for the heavier arrow, vrs 1.2 something for the lighter arrow.
...
Paul
<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face='Verdana, Arial, Helvetica' size=2 id=quote>
Well said, and I'd be willing to hunt with you anytime!
The 456 grain arrow drops about 5 inches between 20 and 25 yards, the 312 grain arrow drops about 4 inches between 20 and 25 yards.
IMHO, you might want to think about switching to the 456 (or sticking to it, I can't tell which arrow it is that you normally shoot).
...
I will tell you this though, and it actaully agrees with your above statement. My bow likes a heavier arrow as far as the amount of energy it will devolop. I went to a shop and chronoed some different arrows at different draw weights and then came home and entered the data into the Archer Program. What I found is my Perfomance factor goes up with the heavier arrow. I only got 183 fps out of a 456 grn arrow at 42 lbs. But when I compared it to a 312 grn arrow moving at 214 fps the performance factor was way higher. Like 1.4 for the heavier arrow, vrs 1.2 something for the lighter arrow.
...
Paul
<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face='Verdana, Arial, Helvetica' size=2 id=quote>
Well said, and I'd be willing to hunt with you anytime!
The 456 grain arrow drops about 5 inches between 20 and 25 yards, the 312 grain arrow drops about 4 inches between 20 and 25 yards.
IMHO, you might want to think about switching to the 456 (or sticking to it, I can't tell which arrow it is that you normally shoot).
12-31-2002 | 11:25 AM
#9
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RE: Light arrows bad choice for hunting
I guess what it comes down to for me is this.
1. I want accuracy. When I practice with my broadheads, I can only shoot one arrow at a given target with my setup because of fear of hitting arrows. I have killed to many arrows that way and can't afford to through arrows away because of hitting them with broadheads. I must say that I am more accurate with heavier arrows then light arrows. (I only shoot fixed bladed broadheads while hunting).
2. I want max penetration. I want pass throughs. Sure, there are agruements that speed will make up for penetration with light arrows, but downrange heavier arrows will carry more penetration potential.
3. I want as much of my bows energy transfered to my arrow as possible. I want to reduce energy transferred to other factors such as hand shock, etc.
4. I want to keep my setup as quiet as possible.
Sure, the trajectory is not as good as a fast, light arrow. I do carry a range finder in the woods with me and know objects up to 30 yards in all directions before I even hunt.
P.S. If you are looking for Arthur, he posts occasionally in the Trad Room, and I agree that Arthur has posted with exceptional wisdom on the Bowhunting thread. It is a shame that certain idividuals may have driven him off this thread. Everyone has opinions, however, respect is something everyone deserves.
Edited by - BobCo19-65 on 12/31/2002 12:32:59
1. I want accuracy. When I practice with my broadheads, I can only shoot one arrow at a given target with my setup because of fear of hitting arrows. I have killed to many arrows that way and can't afford to through arrows away because of hitting them with broadheads. I must say that I am more accurate with heavier arrows then light arrows. (I only shoot fixed bladed broadheads while hunting).
2. I want max penetration. I want pass throughs. Sure, there are agruements that speed will make up for penetration with light arrows, but downrange heavier arrows will carry more penetration potential.
3. I want as much of my bows energy transfered to my arrow as possible. I want to reduce energy transferred to other factors such as hand shock, etc.
4. I want to keep my setup as quiet as possible.
Sure, the trajectory is not as good as a fast, light arrow. I do carry a range finder in the woods with me and know objects up to 30 yards in all directions before I even hunt.
P.S. If you are looking for Arthur, he posts occasionally in the Trad Room, and I agree that Arthur has posted with exceptional wisdom on the Bowhunting thread. It is a shame that certain idividuals may have driven him off this thread. Everyone has opinions, however, respect is something everyone deserves.
Edited by - BobCo19-65 on 12/31/2002 12:32:59
12-31-2002 | 11:34 AM
#10
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From: Murrysville PA USA
RE: Light arrows bad choice for hunting
<BLOCKQUOTE id=quote<font size=1 face='Verdana, Arial, Helvetica' id=quote>quote:<hr height=1 noshade id=quote>
So you found a web page<img src=icon_smile_wink.gif border=0 align=middle><img src=icon_smile_evil.gif border=0 align=middle>
If you use the formula for discovering K.E.,you will find that K.E. changes very little at all with weight of the arrow.
It is more important to shoot the correct bow weight than to fool with grs. per. pound in arrow weight.
There is a reason that states provide for a minimum bow weight for hunting and do not refer to arrow weight...
As far as being "A FOOL", it is better to keep one's mouth closed and be considered a fool than to open it and remove all doubt!
<img src=icon_smile_wink.gif border=0 align=middle><img src=icon_smile_big.gif border=0 align=middle>
<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face='Verdana, Arial, Helvetica' size=2 id=quote>
YES, the bow weight is more important - but once you have chosen a bow weight, you still must choose an arrow.
YES, the initial KE is almost the same, It is only different because of the differing dynamic efficiencies of the bow. It is my belief that this change will be about 10% or a little bit better improvement when going to the 9 grain per pound arrow from a 5 grain per pound arrow.
But the heavier arrow also slows down less on the way to its target.
And it is momentum that leads to penetration, the momentum of the heavier arrow is more.
I am playing the fool a little - I believe that a person can be an ethical hunter at 7 or 6 or even 5 grains per pound, but I think that if we beat this to death we will come to a concensus that going to 9 grains per pound would decrease the number of wounded deer...
beprepn
So you found a web page<img src=icon_smile_wink.gif border=0 align=middle><img src=icon_smile_evil.gif border=0 align=middle>
If you use the formula for discovering K.E.,you will find that K.E. changes very little at all with weight of the arrow.
It is more important to shoot the correct bow weight than to fool with grs. per. pound in arrow weight.
There is a reason that states provide for a minimum bow weight for hunting and do not refer to arrow weight...
As far as being "A FOOL", it is better to keep one's mouth closed and be considered a fool than to open it and remove all doubt!
<img src=icon_smile_wink.gif border=0 align=middle><img src=icon_smile_big.gif border=0 align=middle>
<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face='Verdana, Arial, Helvetica' size=2 id=quote>
YES, the bow weight is more important - but once you have chosen a bow weight, you still must choose an arrow.
YES, the initial KE is almost the same, It is only different because of the differing dynamic efficiencies of the bow. It is my belief that this change will be about 10% or a little bit better improvement when going to the 9 grain per pound arrow from a 5 grain per pound arrow.
But the heavier arrow also slows down less on the way to its target.
And it is momentum that leads to penetration, the momentum of the heavier arrow is more.
I am playing the fool a little - I believe that a person can be an ethical hunter at 7 or 6 or even 5 grains per pound, but I think that if we beat this to death we will come to a concensus that going to 9 grains per pound would decrease the number of wounded deer...
beprepn