Who said that physics wasn't fun?
04-14-2007, 02:38 PM
#261
Giant Nontypical
Join Date: Feb 2003
Location: HENDERSON KY USA
Posts: 6,634
RE: Who said that physics wasn't fun?
ORIGINAL: davepjr71
That's impossible. You can't have 2 seperate arrow weights have the right spine for your bow!!!!
ORIGINAL: TFOX
Here are charts for 2 different weight arrow that are PROPERLY spined and setup for my bow.
I have posted this before but pay close attention to the speed and energy.
PAY EXTRA ATTENTION TO THE DROP PER YARD DIFFERENCE.THIS IS WHAT WILL BE YOUR MISS DIFFERENCE IN A HUNTING SITUATION BETWEEN A LIGHT AND HEAVIER ARROW.
This example isn't using extreme differences but 61 grains should give you an idea of what to expect.
Here are charts for 2 different weight arrow that are PROPERLY spined and setup for my bow.
I have posted this before but pay close attention to the speed and energy.
PAY EXTRA ATTENTION TO THE DROP PER YARD DIFFERENCE.THIS IS WHAT WILL BE YOUR MISS DIFFERENCE IN A HUNTING SITUATION BETWEEN A LIGHT AND HEAVIER ARROW.
This example isn't using extreme differences but 61 grains should give you an idea of what to expect.
I believe I used a FMJ for one and an ACC for another.The spine deflection for both was very close.
An Easton aluminum 2115 has a spine deflection of .462 and a total weight with my setup of 433 grains
An Easton redline 460 has a spine deflection of .460 and a total weight of 334 grains.
Right at 100 grain difference with almost identical spine deflection and both spine perfectly for my bow.
This is using the same insert weights and fletching.I didn't feel changing the insert weight was necessary to show the comparison of spine.The aluminum shafts would be even heavier if I changed that.
When I was talking about broadheads,I was referring to the large cut expandables,they are designed for massive damage,NOT penetration.I have a lower energy setup and therefore,I utilize heads that have penetration more in mind,smaller cut.
My daughter uses 2 blade heads that are the best for penetration but don't do as much damage.
04-14-2007, 05:27 PM
#263
Giant Nontypical
Join Date: Feb 2003
Location: HENDERSON KY USA
Posts: 6,634
RE: Who said that physics wasn't fun?
Straightarrow,I just made an arrow that had an foc of 23.6% that was under 400 grains.
The secret was it was a traditional light stinger that is tapered and has several wraps of carbon up front.I had a 135 gr point and a normal insert that I did not weigh but I believe it was around 23 grains if memory serves me.I also used 4" feathers.Total weight was 399 grains.
It can be done but it isn't going to be done with normal arrows.
I am off to see how it shoots.
The secret was it was a traditional light stinger that is tapered and has several wraps of carbon up front.I had a 135 gr point and a normal insert that I did not weigh but I believe it was around 23 grains if memory serves me.I also used 4" feathers.Total weight was 399 grains.
It can be done but it isn't going to be done with normal arrows.
I am off to see how it shoots.
04-14-2007, 06:07 PM
#264
Nontypical Buck
Join Date: Feb 2007
Location: Balt, MD (orig: J-town,PA) The bowels of Hell!!!
Posts: 2,188
RE: Who said that physics wasn't fun?
ORIGINAL: TFOX
NOT IMPOSSIBLE
I believe I used a FMJ for one and an ACC for another.The spine deflection for both was very close.
An Easton aluminum 2115 has a spine deflection of .462 and a total weight with my setup of 433 grains
An Easton redline 460 has a spine deflection of .460 and a total weight of 334 grains.
Right at 100 grain difference with almost identical spine deflection and both spine perfectly for my bow.
This is using the same insert weights and fletching.I didn't feel changing the insert weight was necessary to show the comparison of spine.The aluminum shafts would be even heavier if I changed that.
When I was talking about broadheads,I was referring to the large cut expandables,they are designed for massive damage,NOT penetration.I have a lower energy setup and therefore,I utilize heads that have penetration more in mind,smaller cut.
My daughter uses 2 blade heads that are the best for penetration but don't do as much damage.
NOT IMPOSSIBLE
I believe I used a FMJ for one and an ACC for another.The spine deflection for both was very close.
An Easton aluminum 2115 has a spine deflection of .462 and a total weight with my setup of 433 grains
An Easton redline 460 has a spine deflection of .460 and a total weight of 334 grains.
Right at 100 grain difference with almost identical spine deflection and both spine perfectly for my bow.
This is using the same insert weights and fletching.I didn't feel changing the insert weight was necessary to show the comparison of spine.The aluminum shafts would be even heavier if I changed that.
When I was talking about broadheads,I was referring to the large cut expandables,they are designed for massive damage,NOT penetration.I have a lower energy setup and therefore,I utilize heads that have penetration more in mind,smaller cut.
My daughter uses 2 blade heads that are the best for penetration but don't do as much damage.
04-14-2007, 06:10 PM
#265
Nontypical Buck
Join Date: Feb 2007
Location: Balt, MD (orig: J-town,PA) The bowels of Hell!!!
Posts: 2,188
RE: Who said that physics wasn't fun?
ORIGINAL: Straightarrow
You need to carefully re-read the report. Take a careful look at the graph.
First, his test are in animals, not foam. Second, none of his arrows were light weight. Third, he states in no uncertain terms, that substantial gain in penetration didn't occur until around 19% FOC. None of your test arrows are even close to that. Fourth, look at the graph and notice that the 14% and 16% FOC arrows had less penetration than the 12% FOC arrows. In other words, FOC is only a benefit when it's real high. He does say that more testing is needed to finalize his conclusions on this. He does say that initial testing does suggest that only extreme FOC arrows are advantageous in penetration. None of your test arrows approached this.
The point is, your test was with normal FOC arrows where his test shows no advantage. If you manage to build a proper arrow with an FOC of 19% or greater, you will find that it weighs at least 600 grains.
Ashby himself states that a high FOC light arrow will out penetrate a low light FOC by as muc has 50%. Now, if you were going to take that light high FOC arrow and compair it to a low heavy FOC arrow where would the penetration be tha same? In an earlier post someonse stated that if I shot a 420 gr arrow I would get 1/2" more of penetration. You are taking just one part of Ashby's report and running with it. To me you are in the "The world is flat" catagory.
First, his test are in animals, not foam. Second, none of his arrows were light weight. Third, he states in no uncertain terms, that substantial gain in penetration didn't occur until around 19% FOC. None of your test arrows are even close to that. Fourth, look at the graph and notice that the 14% and 16% FOC arrows had less penetration than the 12% FOC arrows. In other words, FOC is only a benefit when it's real high. He does say that more testing is needed to finalize his conclusions on this. He does say that initial testing does suggest that only extreme FOC arrows are advantageous in penetration. None of your test arrows approached this.
The point is, your test was with normal FOC arrows where his test shows no advantage. If you manage to build a proper arrow with an FOC of 19% or greater, you will find that it weighs at least 600 grains.
04-14-2007, 06:12 PM
#266
Nontypical Buck
Join Date: Feb 2007
Location: Balt, MD (orig: J-town,PA) The bowels of Hell!!!
Posts: 2,188
RE: Who said that physics wasn't fun?
ORIGINAL: Arthur P
Really? That's news to me, and I'm sure to a whole lot of others as well. [8D]
Let's see.... Arrows that are properly spined for my bow using feathers and 125 gn heads at 32" long and their weights.
Easton XX75 2419 651 Grains
" " " " 2317 610 grains
" " ACC 3-71474 grains
Beman ICS 300 467 grains
I could also use Carbon Express weight tubes, or weedeater line, orpack them with foamand really buck up the weight of the Bemans without impacting their spine at all.
That's impossible. You can't have 2 seperate arrow weights have the right spine for your bow!!!!
Let's see.... Arrows that are properly spined for my bow using feathers and 125 gn heads at 32" long and their weights.
Easton XX75 2419 651 Grains
" " " " 2317 610 grains
" " ACC 3-71474 grains
Beman ICS 300 467 grains
I could also use Carbon Express weight tubes, or weedeater line, orpack them with foamand really buck up the weight of the Bemans without impacting their spine at all.
04-14-2007, 06:25 PM
#267
Giant Nontypical
Join Date: Feb 2003
Location: HENDERSON KY USA
Posts: 6,634
RE: Who said that physics wasn't fun?
If I saw anyone refer to a heavy and light arrow not being able to spine the same,I might have been able to pick up on it but I don't recall it happening.
The wink can have more than one meaning and sarcasm doesn't translate well through the keyboard.
The wink can have more than one meaning and sarcasm doesn't translate well through the keyboard.
04-14-2007, 06:43 PM
#268
Nontypical Buck
Join Date: Dec 2006
Location: Normal, IL
Posts: 1,552
RE: Who said that physics wasn't fun?
TFOX, thats pretty interesting stuff. It is true, the difference in trajectory isnt a whole lot. Even though it was only a difference of 61 grains. I would be very interested in seeing what the difference would be for lets say a 350grain arrow compared to a 650grain arrow. I believe that when people are saying how much more a heavier arrow can penetrate than a light one, theyre compairing extremes. So just for sh*ts and giggles Id like to see a chart showing an extremely light arrow compared to a extremely heavy one.
04-14-2007, 06:56 PM
#269
Nontypical Buck
Join Date: Feb 2007
Location: Balt, MD (orig: J-town,PA) The bowels of Hell!!!
Posts: 2,188
RE: Who said that physics wasn't fun?
ORIGINAL: TFOX
If I saw anyone refer to a heavy and light arrow not being able to spine the same,I might have been able to pick up on it but I don't recall it happening.
The wink can have more than one meaning and sarcasm doesn't translate well through the keyboard.
If I saw anyone refer to a heavy and light arrow not being able to spine the same,I might have been able to pick up on it but I don't recall it happening.
The wink can have more than one meaning and sarcasm doesn't translate well through the keyboard.
I'm trying to lighten the mood in here. We've beat this horse dead.
Read Arthur's post about shooting cans and plastic bottles. It lightened my mood in a hurry.
http://www.huntingnet.com/forum/tm.aspx?m=2090937
04-14-2007, 07:19 PM
#270
Giant Nontypical
Join Date: Feb 2003
Location: HENDERSON KY USA
Posts: 6,634
RE: Who said that physics wasn't fun?
Here you go passthru
35 yard shot for 30 would be approximately 9.5" low with a 367 grain arrow FOR ME
35 yard shot for 30 would be approximately 15.5" low with a 667 grain arrow.AGAIN,FOR ME.
I believe the light arrow would be a wounded deer on a perfect shot and the heavy arrow would be a missed deer on a perfect shot.
Higher energy setups would yield different results.
When talking 300 grains difference,there is a considerable difference in the miss distance.
35 yard shot for 30 would be approximately 9.5" low with a 367 grain arrow FOR ME
35 yard shot for 30 would be approximately 15.5" low with a 667 grain arrow.AGAIN,FOR ME.
I believe the light arrow would be a wounded deer on a perfect shot and the heavy arrow would be a missed deer on a perfect shot.
Higher energy setups would yield different results.
When talking 300 grains difference,there is a considerable difference in the miss distance.