More arrow speed drivel... Trajectory chart
12-12-2007, 06:30 PM
#41
Nontypical Buck
Join Date: Feb 2003
Location: Middletown PA United States
Posts: 3,625
RE: More arrow speed drivel... Trajectory chart
I know for a fact that this chart doesn't hold up as I did it for myself a few years ago. The bow was a 2003 Pearson Freedom. I happened to be shooting really well the chosen day, averaging less than two inch groups at 40 yards.
According to the chart, and using my 20 yard pin to shoot 40 yards, my groups were hitting 16" low. Now if you look at the chart my bow's speed should have been right around 294-295 fps. The fact is the bow was shot over 3 chrono's and was actually propelling an arrow at 264 fps.
I'd say a 30 yard discrepancy isn't even a decent ball-park figure.
According to the chart, and using my 20 yard pin to shoot 40 yards, my groups were hitting 16" low. Now if you look at the chart my bow's speed should have been right around 294-295 fps. The fact is the bow was shot over 3 chrono's and was actually propelling an arrow at 264 fps.
I'd say a 30 yard discrepancy isn't even a decent ball-park figure.
12-12-2007, 06:43 PM
#42
Giant Nontypical
Join Date: Feb 2003
Location: HENDERSON KY USA
Posts: 6,634
RE: More arrow speed drivel... Trajectory chart
Have you EVER actually compared a fast arrowOUT OF YOUR BOWverses a slow arrow?
That chart is useless in real world hunting situations.
Most of us use pins so all we are concerned with is how much difference there will be between a slow bow/arrow if we misjudge by 5 yards or so at a given distance,quess what,the difference is so small that most aren't good enough shots to see the difference at 40 yards.Plus,if you misjudge by 5 yards at 40 yards,chances are you didn't get the animal anyways.
EXTREME differences in speed will yield a noticable difference but not real world differences.
You MAY see a difference when using 1 pin but if one knows how to setup a 1 pin sight,they will see little differenc in most cases at hunting distances,especially for 1 pin distances.
This argument is OLD and has been discussed many times and I have actually seen a few come back after actually testing the mis difference in real world hunting distances and say the difference was very small.
That chart is useless in real world hunting situations.
Most of us use pins so all we are concerned with is how much difference there will be between a slow bow/arrow if we misjudge by 5 yards or so at a given distance,quess what,the difference is so small that most aren't good enough shots to see the difference at 40 yards.Plus,if you misjudge by 5 yards at 40 yards,chances are you didn't get the animal anyways.
EXTREME differences in speed will yield a noticable difference but not real world differences.
You MAY see a difference when using 1 pin but if one knows how to setup a 1 pin sight,they will see little differenc in most cases at hunting distances,especially for 1 pin distances.
This argument is OLD and has been discussed many times and I have actually seen a few come back after actually testing the mis difference in real world hunting distances and say the difference was very small.
12-12-2007, 06:45 PM
#43
Giant Nontypical
Join Date: Feb 2003
Location: HENDERSON KY USA
Posts: 6,634
RE: More arrow speed drivel... Trajectory chart
ORIGINAL: BGfisher
I know for a fact that this chart doesn't hold up as I did it for myself a few years ago. The bow was a 2003 Pearson Freedom. I happened to be shooting really well the chosen day, averaging less than two inch groups at 40 yards.
According to the chart, and using my 20 yard pin to shoot 40 yards, my groups were hitting 16" low. Now if you look at the chart my bow's speed should have been right around 294-295 fps. The fact is the bow was shot over 3 chrono's and was actually propelling an arrow at 264 fps.
I'd say a 30 yard discrepancy isn't even a decent ball-park figure.
I know for a fact that this chart doesn't hold up as I did it for myself a few years ago. The bow was a 2003 Pearson Freedom. I happened to be shooting really well the chosen day, averaging less than two inch groups at 40 yards.
According to the chart, and using my 20 yard pin to shoot 40 yards, my groups were hitting 16" low. Now if you look at the chart my bow's speed should have been right around 294-295 fps. The fact is the bow was shot over 3 chrono's and was actually propelling an arrow at 264 fps.
I'd say a 30 yard discrepancy isn't even a decent ball-park figure.
I haven't been reading all the responses so this could have been asked or addressed.
Maybe the chart shows actuall drop and doesn't take into consideration that a bow is actually pointed UP when fired.The chart is probably showing what would happen if the bow was fired parralel to the ground.
I just went back and looked at the chart again and I have no idea where they came up with their numbers.
12-12-2007, 06:54 PM
#44
Giant Nontypical
Join Date: Feb 2003
Location: HENDERSON KY USA
Posts: 6,634
RE: More arrow speed drivel... Trajectory chart
Just went back throgh this thread and came across this.
You really need to get out there and do as Rick/Matt has done and I have done.
I also have spent hours looking at ballistic calculators and the cost of getting the 330 usually isn't worth it.
He is comparing 40 fps and I have compared 20 fps OUT OF THE SAME bow and on a 3 yard miss of yardage @ 40 yards,the difference of point of impact was 1/2"
This was from a lower energy bow to begin with.
ORIGINAL: quiksilver
No way.The only way you could get those results would be to play games with the sights/arrows. I.E. Set up the slow bow "just a touch" hot at 20, and the fast bow just a tad bit low... Maybe put feathers and an ultralight arrow on the fast bow, blazers and a heavy arrow on the slow one. Playing games with the trajectory andspeed retention- Cheating. You could come close. But no way is there 1" of difference between those two bows, as described.
The Physics: 2 objects traveling 120 feet, with one at 315 and the second at 275...
(I'm horrible at math, so if I'm wrong - just show me what I did wrong)
Object 1 will be in the air for .38 seconds, while Object 2 will be in the air for .44 seconds, a difference of .06 seconds.
275/1 = 120/.44 and 315/1 = 120/.38
In .38 seconds, a falling body will fall 27"
In .44 seconds, falling body #2 will fall 37"
d(meters1)=1/2(9.8)(.38)(.38)
d(meters1)=.70756
d(inches1)= .70756 x 39
d(inches1)= 27
d(meters2)=1/2(9.8)(.44)(.44)
d(meters2)=.94864
d(inches2)=.94864 x 39
d(inches2)= 37
The differencebetween a 275fps arrow and a 315fps arrow is less than an inch at 40 yards.
The Physics: 2 objects traveling 120 feet, with one at 315 and the second at 275...
(I'm horrible at math, so if I'm wrong - just show me what I did wrong)
Object 1 will be in the air for .38 seconds, while Object 2 will be in the air for .44 seconds, a difference of .06 seconds.
275/1 = 120/.44 and 315/1 = 120/.38
In .38 seconds, a falling body will fall 27"
In .44 seconds, falling body #2 will fall 37"
d(meters1)=1/2(9.8)(.38)(.38)
d(meters1)=.70756
d(inches1)= .70756 x 39
d(inches1)= 27
d(meters2)=1/2(9.8)(.44)(.44)
d(meters2)=.94864
d(inches2)=.94864 x 39
d(inches2)= 37
You really need to get out there and do as Rick/Matt has done and I have done.
I also have spent hours looking at ballistic calculators and the cost of getting the 330 usually isn't worth it.
He is comparing 40 fps and I have compared 20 fps OUT OF THE SAME bow and on a 3 yard miss of yardage @ 40 yards,the difference of point of impact was 1/2"
This was from a lower energy bow to begin with.
12-12-2007, 07:20 PM
#45
Giant Nontypical
Thread Starter
Join Date: Feb 2003
Posts: 5,716
RE: More arrow speed drivel... Trajectory chart
Tfox - you've already pointed out why you're getting different "real world" results than the ballistics calculation: Your bow is pointed "up" when it goes off. You're talking about a 3 yard misjudge with human error...and acting lke it's some kind of smoking gun that your slower arrow only drops and extra 1/2"over 3 yards at 40 yards...Think about whatyou're telling me...if 20 fps makes1/2" of difference over 3 yards, using the 40 YARD PIN. Try it with the 20 yard mark... See if it's still 1/2". HINT: It won't be.
Math doesn't lie. You can sit here and swear on your mother's grave that your arrow only drops 1" between 20 and 30 - no skin off my back bro. But I've shot enough to know that these calculations are fairly accurate - but you have to understand what the numbers are actually saying, and how that relates to the real world- and then how to manipulate the results.
Boy, you and Smartie Artie sure do get jacked up over a little physics. Like I told him- instead of complaining that it's wrong - get out your calculator and show me where I'm wrong.
Math doesn't lie. You can sit here and swear on your mother's grave that your arrow only drops 1" between 20 and 30 - no skin off my back bro. But I've shot enough to know that these calculations are fairly accurate - but you have to understand what the numbers are actually saying, and how that relates to the real world- and then how to manipulate the results.
Boy, you and Smartie Artie sure do get jacked up over a little physics. Like I told him- instead of complaining that it's wrong - get out your calculator and show me where I'm wrong.
12-12-2007, 07:23 PM
#46
Giant Nontypical
Join Date: Feb 2003
Location: HENDERSON KY USA
Posts: 6,634
RE: More arrow speed drivel... Trajectory chart
SORRY 1 more response.
This is a chart of my actuall setup and shows actuall drop when fired parallel to the ground.
The only numbers that a hunter should concern themselves with are amount of drop per yard,that is somewhat close to the miss distance but not exactlt because the bow isn't fired parallel to the ground.
This is all out of the same bow with the same poundage,only difference is the arrow weight and the charts are computer generated so they may be off a little BUT from what I have tested,it is pretty darn close.
ANd here is a slower/heavier arrowMuch heavier.
This would be an example of an extreme difference in speed and arrow weight.290 grain difference in arrow weight,this really isn't a real world showing.
This is more of a real world showing.Compare this to the first one and you will see the difference is minimal at best. 61 grain difference and 17 fps
This is a chart of my actuall setup and shows actuall drop when fired parallel to the ground.
The only numbers that a hunter should concern themselves with are amount of drop per yard,that is somewhat close to the miss distance but not exactlt because the bow isn't fired parallel to the ground.
This is all out of the same bow with the same poundage,only difference is the arrow weight and the charts are computer generated so they may be off a little BUT from what I have tested,it is pretty darn close.
ANd here is a slower/heavier arrowMuch heavier.
This would be an example of an extreme difference in speed and arrow weight.290 grain difference in arrow weight,this really isn't a real world showing.
This is more of a real world showing.Compare this to the first one and you will see the difference is minimal at best. 61 grain difference and 17 fps
12-12-2007, 07:28 PM
#47
Giant Nontypical
Join Date: Feb 2003
Location: HENDERSON KY USA
Posts: 6,634
RE: More arrow speed drivel... Trajectory chart
ORIGINAL: quiksilver
Tfox - you've already pointed out why you're getting different "real world" results than the ballistics calculation: Your bow is pointed "up" when it goes off. You're talking about a 3 yard misjudge with human error...and acting lke it's some kind of smoking gun that your slower arrow only drops and extra 1/2"over 3 yards at 40 yards...Think about whatyou're telling me...if 20 fps makes1/2" of difference over 3 yards, using the 40 YARD PIN. Try it with the 20 yard mark... See if it's still 1/2". HINT: It won't be.
Math doesn't lie. You can sit here and swear on your mother's grave that your arrow only drops 1" between 20 and 30 - no skin off my back bro. But I've shot enough to know that these calculations are fairly accurate - but you have to understand what the numbers are actually saying, and how that relates to the real world- and then how to manipulate the results.
Boy, you and Smartie Artie sure do get jacked up over a little physics. Like I told him- instead of complaining that it's wrong - get out your calculator and show me where I'm wrong.
Tfox - you've already pointed out why you're getting different "real world" results than the ballistics calculation: Your bow is pointed "up" when it goes off. You're talking about a 3 yard misjudge with human error...and acting lke it's some kind of smoking gun that your slower arrow only drops and extra 1/2"over 3 yards at 40 yards...Think about whatyou're telling me...if 20 fps makes1/2" of difference over 3 yards, using the 40 YARD PIN. Try it with the 20 yard mark... See if it's still 1/2". HINT: It won't be.
Math doesn't lie. You can sit here and swear on your mother's grave that your arrow only drops 1" between 20 and 30 - no skin off my back bro. But I've shot enough to know that these calculations are fairly accurate - but you have to understand what the numbers are actually saying, and how that relates to the real world- and then how to manipulate the results.
Boy, you and Smartie Artie sure do get jacked up over a little physics. Like I told him- instead of complaining that it's wrong - get out your calculator and show me where I'm wrong.
If I shoot a 40 yard deer for 20 I blew it REGARDLESS OF SPEED SO IT DOESN"T MATTER,.That is the real world results most of us refer to.
12-12-2007, 07:30 PM
#48
Giant Nontypical
Thread Starter
Join Date: Feb 2003
Posts: 5,716
RE: More arrow speed drivel... Trajectory chart
TFox - those numbers definitely lookpretty close to what the ballistics calculator is spitting out - with a 20 yard zero.
Thanks for posting those. Most of us don't have access to that software, but that goes to show you - just a simple online calculator will get you in the ballpark.
Alsoshows those (Art)who werequestioning the "vacuum" calculationsthat the "Speed Degradation" within a normal archery effective range (50 yds)isn't really enough to be concerned about.
Thanks for posting those. Most of us don't have access to that software, but that goes to show you - just a simple online calculator will get you in the ballpark.
Alsoshows those (Art)who werequestioning the "vacuum" calculationsthat the "Speed Degradation" within a normal archery effective range (50 yds)isn't really enough to be concerned about.
12-12-2007, 07:40 PM
#49
Giant Nontypical
Join Date: Feb 2003
Location: HENDERSON KY USA
Posts: 6,634
RE: More arrow speed drivel... Trajectory chart
ORIGINAL: quiksilver
TFox - those numbers definitely lookpretty close to what the ballistics calculator is spitting out - with a 20 yard zero.
Thanks for posting those. Most of us don't have access to that software, but that goes to show you - just a simple online calculator will get you in the ballpark.
Alsoshows those (Art)who werequestioning the "vacuum" calculationsthat the "Speed Degradation" within a normal archery effective range (50 yds)isn't really enough to be concerned about.
TFox - those numbers definitely lookpretty close to what the ballistics calculator is spitting out - with a 20 yard zero.
Thanks for posting those. Most of us don't have access to that software, but that goes to show you - just a simple online calculator will get you in the ballpark.
Alsoshows those (Art)who werequestioning the "vacuum" calculationsthat the "Speed Degradation" within a normal archery effective range (50 yds)isn't really enough to be concerned about.
These charts take into account many variables.
BUT,like I said,the only number that really matters is the drop per yard number.
It doesn't even work for 1 pin shooters because the bow is being shot parallel to the ground.
I BELIEVE this is the trajectory chart for my hunting setup at 257 fps.
Not sure and my program isn't working right now,this was saved.
As you can see,at 40 yards,I can hit the vitals from 36 to 43 yards and in most real world cases,I have found that overall distance changes by LESS than a yard at each end with a speed bow and a slow hunting bow.
12-12-2007, 07:44 PM
#50
Join Date: Aug 2006
Location: Eureka, MO
Posts: 1,519
RE: More arrow speed drivel... Trajectory chart
ORIGINAL: quiksilver
It is a cool toy. Kinda makes me wanna order one, then stop at the pet store and buy a parakeet or a rabbitand chase it through the house with a blitzkreig of Nerf Arrows.
ORIGINAL: Germ
Fran you have to admit that is one cool looking toy, and you know when the PPG are on[&:]
Fran you have to admit that is one cool looking toy, and you know when the PPG are on[&:]