HELP.... gram tip/braodhead?
06-13-2003, 03:52 PM
#1
Thread Starter
Join Date: Mar 2003
Location:
Posts: 38
HELP.... gram tip/braodhead?
fianlly I have my new VFT Extreme, (60#, 80%L/O, 28" D/L) and ready to install Trophy Ridge Matrix sight, no-peep & GKF' s new " short" Power Drop just off the presses and ready to consider arrows, this bow is for treestand hunting mainly whitetail & inside 40 yards and I wanted to try a few different weight carbon arrows, I was leaning toward Carbon Express because they have from CX-7g to CX Hunter-8.4 to Terminator-11g so thought I might try a few and check KE and speed......my question is what determines what gram field tip/broadhead to use, 75/100/125? 
and what other arrow considerations should I be aware of?
Thanx for the help
and what other arrow considerations should I be aware of?Thanx for the help
06-14-2003, 08:35 AM
#2
Typical Buck
Join Date: Feb 2003
Location: USA
Posts: 868
RE: HELP.... gram tip/braodhead?
One of the things that needs to be considered is FOC. You want to try to keep your FOC somewhere between 7 - 11% however this is not a hard fast rule, it is whatever flys well for your setup. Increasing tip weight will increase FOC.
Another thing to consider is arrow spine. With your draw length and weight, if you are sitting right on the border between two different shaft spines increasing your tip weight will have the effect of reducing the arrow spine a bit and may push you toward the stiffer of the two shafts.
As far as changes in KE with tip weight, I think you will find that the KE is essentially going to be nearly equal for all arrow weights (possibly just a bit higher for the heavier arrows). What will change is the speed. As your reduce the arrow weight, the speed will increase but KE will be essentially the same.
KE = (arrow weight / 450240) x (velocity x velocity)
The other factor that accompanies the speed change is arrow drop. Obviously a faster arrow will have less drop over the same distance....this is why the 3D shooters are looking for these lightning fast bows with ultra light arrows. An error in yardage estimation does not become such a problem with a flat shooting arrow.
For hunting my personal preference is more in the middle of your arrow weight range. 8.4 to about 9.5 grains per inch shooting a 100 grain tip is what I use.
This gives me a good compromise of speed, arrow weight, drop and downrange energy.
Essentially it comes down to YOUR preference and what shoots well for you.
Some other good brands to look at are:
Gold Tip: Very economical to shoot and stand up very well
Beman: ICS Hunters and ICS Camo Hunters
I have heard that the Vapor arrows fly pretty well but their durability is not that great. No experience with them, only what I have heard.
Another thing to consider is arrow spine. With your draw length and weight, if you are sitting right on the border between two different shaft spines increasing your tip weight will have the effect of reducing the arrow spine a bit and may push you toward the stiffer of the two shafts.
As far as changes in KE with tip weight, I think you will find that the KE is essentially going to be nearly equal for all arrow weights (possibly just a bit higher for the heavier arrows). What will change is the speed. As your reduce the arrow weight, the speed will increase but KE will be essentially the same.
KE = (arrow weight / 450240) x (velocity x velocity)
The other factor that accompanies the speed change is arrow drop. Obviously a faster arrow will have less drop over the same distance....this is why the 3D shooters are looking for these lightning fast bows with ultra light arrows. An error in yardage estimation does not become such a problem with a flat shooting arrow.
For hunting my personal preference is more in the middle of your arrow weight range. 8.4 to about 9.5 grains per inch shooting a 100 grain tip is what I use.
This gives me a good compromise of speed, arrow weight, drop and downrange energy.
Essentially it comes down to YOUR preference and what shoots well for you.
Some other good brands to look at are:
Gold Tip: Very economical to shoot and stand up very well
Beman: ICS Hunters and ICS Camo Hunters
I have heard that the Vapor arrows fly pretty well but their durability is not that great. No experience with them, only what I have heard.
06-14-2003, 09:27 AM
#3
Thread Starter
Join Date: Mar 2003
Location:
Posts: 38
RE: HELP.... gram tip/braodhead?
Thank-you for the info, glad to learn alittle more every day.
I guess the only reason I wanted to try the CX was the 7g weight, being the lightest I found I wanted to see how fast my new bow would shoot, not to really use just to try, by the same token the 11g terminator seemed the heaviest I thought I could try that as well as an inbetween weight arrow and check speed, ke, drop, foc.
(Bow-Tech sent a certificate with it saying draw length 29" , arrow gram weight 300, speed 311fps)
(Again this is for treestand hunting inside of 40 yds)
To find the weight field tip/broadhead (ie:75/100/125) I want to use do I check the weight of a arrow I want to try and figure the % FOC with different weight tip to find 1 that will make the arrow 7-11% FOC?
I have the formula for KE, how do I figure arrow drop at different arrow weights, and is there a measurable difference inside of 40 yards?
How straight do lighter arrows shoot verses heavier arrows, do the heavier shoot truer, mesurable?
Oh course I' d like it all, straightest (flatest) shooting inside of 40 yards, pleanty of KE for at least whitetail as well as speed in that order.
I have the new bow listed above so it should produce enough speed to allow be to go with a heavier arrow if that shoots truer with pleanty of KE? Am I thinking on the right lines?
I assume my local archery shop can help me but I like to know alittle more myself before getting there.
Thanx again forthe help
I guess the only reason I wanted to try the CX was the 7g weight, being the lightest I found I wanted to see how fast my new bow would shoot, not to really use just to try, by the same token the 11g terminator seemed the heaviest I thought I could try that as well as an inbetween weight arrow and check speed, ke, drop, foc.
(Bow-Tech sent a certificate with it saying draw length 29" , arrow gram weight 300, speed 311fps)
(Again this is for treestand hunting inside of 40 yds)
To find the weight field tip/broadhead (ie:75/100/125) I want to use do I check the weight of a arrow I want to try and figure the % FOC with different weight tip to find 1 that will make the arrow 7-11% FOC?
I have the formula for KE, how do I figure arrow drop at different arrow weights, and is there a measurable difference inside of 40 yards?
How straight do lighter arrows shoot verses heavier arrows, do the heavier shoot truer, mesurable?
Oh course I' d like it all, straightest (flatest) shooting inside of 40 yards, pleanty of KE for at least whitetail as well as speed in that order.
I have the new bow listed above so it should produce enough speed to allow be to go with a heavier arrow if that shoots truer with pleanty of KE? Am I thinking on the right lines?
I assume my local archery shop can help me but I like to know alittle more myself before getting there.
Thanx again forthe help
06-15-2003, 12:20 AM
#4
Boone & Crockett
Join Date: Feb 2003
Posts: 10,679
RE: HELP.... gram tip/braodhead?
Go to http://bowjackson.com/ and they have a bunch of different calculators to figure KE, FOC, Arrow trajectory, ETC...
You do not need to shoot 300 fps to hunt inside of 40 yards. 250+ will be plenty fast. Your Bowtech will certainly produce enough speed and KE to hunt anything that you want to. To decide on a head weight the only real good way is to buy field tips in different weights and just shoot to see which one flys better. You may need to do some minor tweeking of the bow when switching different weights. Usually on an average hunting weight arrow the 100 and 125 grain heads fly the best.
One more thing to think about is that the faster the arrow the more fletching control you may need when using fixed broadheads. Longer vanes or more helical or offset of the vanes.
You do not need to shoot 300 fps to hunt inside of 40 yards. 250+ will be plenty fast. Your Bowtech will certainly produce enough speed and KE to hunt anything that you want to. To decide on a head weight the only real good way is to buy field tips in different weights and just shoot to see which one flys better. You may need to do some minor tweeking of the bow when switching different weights. Usually on an average hunting weight arrow the 100 and 125 grain heads fly the best.
One more thing to think about is that the faster the arrow the more fletching control you may need when using fixed broadheads. Longer vanes or more helical or offset of the vanes.
