Post by: Nice Racks on June 18, 2014, 09:49:46 PM
Post by: Rainier10 on June 18, 2014, 10:05:19 PM
Post by: brianb231 on June 18, 2014, 10:35:58 PM
Post by: RadSav on June 18, 2014, 11:23:50 PM
Typically, an arrow will lose about 1% of its velocity (and momentum) and 2% of its kinetic energy at 40 yards and 2% of its velocity (and momentum) and 4% of its kinetic energy at 80 yards. Of this, we are absolutely certain.A 300 fps bow/arrow combination that only loses 2% or 6 fps between zero and 80 yards is a bow/arrow setup I want to shoot!!! If I did my math right (of which I am making no guarantees tonight) ;) I'm showing that would put a total arrow drop at 80 yards between 38 and 40 inches (with a rough guestimate). That is about 95" better than my bow shoots!
Download Archers Advantage and input your bows specifics. If you want to know speed and ke at different yardages it will calculate those for you under the "Preview Marks" file tab. http://www.archersadvantage.com/ (http://www.archersadvantage.com/)
For instance my new Agenda 7 shooting A/C/C 340's @ 62# has a point blank speed of 292 and 80.2 ke. The following calculations in percentages are the lost performance every ten yards to 80. For my bow of course as each bow arrow combination will be different.
10 Yards = 1.63% loss in speed / 3.2% loss in KE
20 yards = 3.23% loss in speed / 6.4% loss in KE
30 yards = 4.81% loss in speed / 9.4% loss in KE
40 yards = 6.37% loss in speed / 12.3% loss in KE
50 yards = 7.91% loss in speed / 15.2% loss in KE
60 yards = 9.43% loss in speed / 18.0% loss in KE
70 yards = 10.92% loss in speed / 20.7% loss in KE
80 yards = 12.40% loss in speed / 23.3% loss in KE
(134.7" total drop)(loss of 36.2 fps)(loss of 18.7 ft-lb KE)
If kinetic energy really meant much of anything in bowhunting North American game I might have to be concerned looking at those numbers. Fortunately it really doesn't mean much of anything unless you are a girl or a 10 year old boy.
Post by: brianb231 on June 19, 2014, 07:26:52 AM
Typically, an arrow will lose about 1% of its velocity (and momentum) and 2% of its kinetic energy at 40 yards and 2% of its velocity (and momentum) and 4% of its kinetic energy at 80 yards. Of this, we are absolutely certain.A 300 fps bow/arrow combination that only loses 2% or 6 fps between zero and 80 yards is a bow/arrow setup I want to shoot!!! If I did my math right (of which I am making no guarantees tonight) ;) I'm showing that would put a total arrow drop at 80 yards between 38 and 40 inches (with a rough guestimate). That is about 95" better than my bow shoots!
I googled a website and cut and pasted that information. I was quite surprised as well.
Here is the website for a read. Just thought I would see if I could provide some info.
http://www.africanarcher.com/arrowMomentum.html (http://www.africanarcher.com/arrowMomentum.html)
:tung:
Download Archers Advantage and input your bows specifics. If you want to know speed and ke at different yardages it will calculate those for you under the "Preview Marks" file tab. http://www.archersadvantage.com/ (http://www.archersadvantage.com/)
For instance my new Agenda 7 shooting A/C/C 340's @ 62# has a point blank speed of 292 and 80.2 ke. The following calculations in percentages are the lost performance every ten yards to 80. For my bow of course as each bow arrow combination will be different.
10 Yards = 1.63% loss in speed / 3.2% loss in KE
20 yards = 3.23% loss in speed / 6.4% loss in KE
30 yards = 4.81% loss in speed / 9.4% loss in KE
40 yards = 6.37% loss in speed / 12.3% loss in KE
50 yards = 7.91% loss in speed / 15.2% loss in KE
60 yards = 9.43% loss in speed / 18.0% loss in KE
70 yards = 10.92% loss in speed / 20.7% loss in KE
80 yards = 12.40% loss in speed / 23.3% loss in KE
(134.7" total drop)(loss of 36.2 fps)(loss of 18.7 ft-lb KE)
If kinetic energy really meant much of anything in bowhunting North American game I might have to be concerned looking at those numbers. Fortunately it really doesn't mean much of anything unless you are a girl or a 10 year old boy.
Post by: RadSav on June 19, 2014, 03:00:33 PM
My usual instincts after reading way too many of these copy cat articles, since the dentist got popular, is to ignore anything that tries to correlate Ke to penetration. The dentist has been the only one to ever present a case with a solid foundation. And even then, as mentioned, his writings have been quite close minded and incomplete in many areas.
Ashby is a good read though. Just readers should beware the focus in narrow and riddled with traditional bias. And, as he states many of the things people love to concentrate on in his writings he has listed quite low on his scale of importance. In his defense he has not tried to hide this! It just seems his #8 thru 10 seem to be the things everyone wants to talk about :rolleyes: That is not really his fault!
Claiming to be the first to ever do the African studies when Savora did similar studies years prior in conjunction with the Rhodesian government...well yeah! That is his fault :chuckle: Oddly enough the Rhodesian government concluded those devices the dentist has become famous for should be outlawed for use in African game hunting. It took Savora and one of the Wardens (I forget his name right now) quite a bit of effort to explain you really can not accept one without the other. Their efforts are the only reason the dentist was ever allowed to do what he did years later. Yet the dentist attempts to take all the credit.
Post by: sakoshooter on June 19, 2014, 10:18:46 PM
http://archeryreport.com/2010/09/arrow-foc-basics-calculate/ (http://archeryreport.com/2010/09/arrow-foc-basics-calculate/)