Tndeer Logo

Page all of 2 12>
Topic Options
#2898020 - 08/06/12 02:56 PM Setting CrossBow Scope Questions
fairchaser
8 Point


Registered: 09/13/11
Posts: 1215
Loc: TN, USA

Offline
I have an Excalibur Crossbow that shoots 330 FPS and have the scope adjusted so that from the ground, it shoots accurately for the multi-lines at 10-50 yards. My question is could the speed adjustment on the scope be adjusted to accurately compensate for a tree stand angle? The X bow should shoot high using the yardage measured from an elevated position, so I was thinking I could adjust the speed on the scope a little faster to compensate for this. Anyone have any experience here?
_________________________
"I always wanted to do something that was unequivocal" Charles Morris played by Anthony Hopkins in the movie the Edge.

Top
#2898066 - 08/06/12 03:53 PM Re: Setting CrossBow Scope Questions [Re: fairchaser]
Rubberduck270
10 Point


Registered: 11/01/10
Posts: 2804
Loc: Lawrence Co.

Offline
It will shoot the same as long as you go by the horizontal distance rather than the line of sight. Meaning, rather than estimating how far the deer is from your eyeball (line of sight) estimate his distance from the bottom of your stand.

That being said, the effect that the height of your stand has on the arrow is negligible. I know alot of rangefinder companies have made a ton off of ARC (angle range compensation or something similar) but it's really not worth it.

Say you are shooting on a 45 degree angle (i.e. You're 15 ft up a tree and the deer is 15 ft from the base of your tree). From your eyeball to the deer is ~21 ft. Not sure about your crossbow but mine is deadnuts with the first mark out to 25 yards, therefore you're gonna use the first crosshair from 0-25 yards. The 6ft difference isn't worth worrying about.

Moving out a little farther and say the deer is at 20 yards and you are still 15 ft up the tree. From your eyeball to the deer is 20.6 yrds, so you're still using your first crosshair.

Jump way on out to 50 yrds. with you still 15 ft up the tree. Line of sight distance is 50.25 yrds, so you're still using your 50 yrd crosshair.

Worrying about the difference your height makes isn't really worth your time. If you have it dialed in from the ground you won't have anything to worry about come opening morning when he steps out within ~50yrds.
_________________________
Smokeless Muzzleloading: It ain't your Grampa's flintlock

Top
#2898288 - 08/06/12 08:10 PM Re: Setting CrossBow Scope Questions [Re: Rubberduck270]
fairchaser
8 Point


Registered: 09/13/11
Posts: 1215
Loc: TN, USA

Offline
Thanks Rubberduck. Do you have the formula for the calculation? I am a bit surprised that the difference is so slight once you get out farther but I was never that good with geometry.
_________________________
"I always wanted to do something that was unequivocal" Charles Morris played by Anthony Hopkins in the movie the Edge.

Top
#2898758 - 08/07/12 08:00 AM Re: Setting CrossBow Scope Questions [Re: fairchaser]
Rubberduck270
10 Point


Registered: 11/01/10
Posts: 2804
Loc: Lawrence Co.

Offline
 Originally Posted By: fairchaser
Do you have the formula for the calculation? I am a bit surprised that the difference is so slight once you get out farther but I was never that good with geometry.


It's actually trigonometry rather than geometry.

You use the Pythagorean Theorem. Its the Standard formula for calculating the third side of a right triangle. Where A=Stand Height, B=Horizontal Distance to Target and C=Line of Sight Distance, C=sqrt(A*A + B*B). Or you can use this calculator and find the value of C http://ncalculators.com/number-conversion/pythagoras-theorem.htm/.
_________________________
Smokeless Muzzleloading: It ain't your Grampa's flintlock

Top
#2899040 - 08/07/12 01:04 PM Re: Setting CrossBow Scope Questions [Re: Rubberduck270]
fairchaser
8 Point


Registered: 09/13/11
Posts: 1215
Loc: TN, USA

Offline
 Originally Posted By: Rubberduck270
 Originally Posted By: fairchaser
Do you have the formula for the calculation? I am a bit surprised that the difference is so slight once you get out farther but I was never that good with geometry.


It's actually trigonometry rather than geometry.

You use the Pythagorean Theorem. Its the Standard formula for calculating the third side of a right triangle. Where A=Stand Height, B=Horizontal Distance to Target and C=Line of Sight Distance, C=sqrt(A*A + B*B). Or you can use this calculator and find the value of C http://ncalculators.com/number-conversion/pythagoras-theorem.htm/.



Thanks, that is probably more math than I want to tackle. You ever see a monkey solve a math problem? I will take your word for it RubberDuck. \:D
_________________________
"I always wanted to do something that was unequivocal" Charles Morris played by Anthony Hopkins in the movie the Edge.

Top
#2899094 - 08/07/12 01:41 PM Re: Setting CrossBow Scope Questions [Re: fairchaser]
BlackBelt
10 Point


Registered: 08/09/08
Posts: 3188
Loc: SouthWest TN

Offline
Math makes my head hurt.
Top
#2899220 - 08/07/12 03:46 PM Re: Setting CrossBow Scope Questions [Re: BlackBelt]
Rubberduck270
10 Point


Registered: 11/01/10
Posts: 2804
Loc: Lawrence Co.

Offline
 Originally Posted By: BlackBelt
Math makes my head hurt.


I like it. I also enjoy algebra, trigonometry, statistics, calculus and differential equations. Heck I even enjoy a little mathematics history from time to time.
_________________________
Smokeless Muzzleloading: It ain't your Grampa's flintlock

Top
#2921834 - 08/27/12 09:18 AM Re: Setting CrossBow Scope Questions [Re: Rubberduck270]
holstonangler
6 Point


Registered: 02/25/06
Posts: 959
Loc: Johnson City

Offline
Its more gravity affecting the arrow drop than the actual distance, shooting at downward angles has less gravitational effect on the arrow than shooting horizonally. Thats why there's a difference when shooting high out a treestand as opposed to shooting at ground level.

Edited by holstonangler (08/27/12 09:19 AM)

Top
#2921936 - 08/27/12 10:28 AM Re: Setting CrossBow Scope Questions [Re: holstonangler]
Rubberduck270
10 Point


Registered: 11/01/10
Posts: 2804
Loc: Lawrence Co.

Offline
Gravity affects the arrow the same. No matter if you are shooting horizontally or vertically. The affect of gravity is the same.
_________________________
Smokeless Muzzleloading: It ain't your Grampa's flintlock

Top
#2922093 - 08/27/12 12:59 PM Re: Setting CrossBow Scope Questions [Re: Rubberduck270]
fairchaser
8 Point


Registered: 09/13/11
Posts: 1215
Loc: TN, USA

Offline
 Originally Posted By: Rubberduck270
Gravity affects the arrow the same. No matter if you are shooting horizontally or vertically. The affect of gravity is the same.


Hey Rubberduck:
If you drop an arrow at the same height at the same time that you shoot an arrow will they hit the ground at the same time just like a bullet?
_________________________
"I always wanted to do something that was unequivocal" Charles Morris played by Anthony Hopkins in the movie the Edge.

Top
#2922098 - 08/27/12 01:02 PM Re: Setting CrossBow Scope Questions [Re: holstonangler]
fairchaser
8 Point


Registered: 09/13/11
Posts: 1215
Loc: TN, USA

Offline
 Originally Posted By: holstonangler
Its more gravity affecting the arrow drop than the actual distance, shooting at downward angles has less gravitational effect on the arrow than shooting horizonally. Thats why there's a difference when shooting high out a treestand as opposed to shooting at ground level.


I think it is because it is a shorter distance than the other leg of the triangle.
_________________________
"I always wanted to do something that was unequivocal" Charles Morris played by Anthony Hopkins in the movie the Edge.

Top
#2926166 - 08/30/12 10:07 AM Re: Setting CrossBow Scope Questions [Re: fairchaser]
Rubberduck270
10 Point


Registered: 11/01/10
Posts: 2804
Loc: Lawrence Co.

Offline
 Originally Posted By: fairchaser
Hey Rubberduck:
If you drop an arrow at the same height at the same time that you shoot an arrow will they hit the ground at the same time just like a bullet?


Yes, provided the arrow is shot horizontally.

 Originally Posted By: fairchaser
 Originally Posted By: holstonangler
Its more gravity affecting the arrow drop than the actual distance, shooting at downward angles has less gravitational effect on the arrow than shooting horizonally. Thats why there's a difference when shooting high out a treestand as opposed to shooting at ground level.


I think it is because it is a shorter distance than the other leg of the triangle.


I don't understand what he's saying 100% but I think I know what he's referring to. By shooting at a downward angle gravity is helping your arrow accelerate towards your target, thus affecting the speed of your arrow rather than it's flight path. So, if you were shooting straight down, gravity would have no affect on where your arrow would hit (i.e. no affect on it's flight path) but rather just help speed it along. So in a sense he is correct, at steeper angles gravity's effects on the arrows flight path is lessened. Fairchaiser, you are also correct in saying that it is because of the shorter horizontal distance because the steeper the angle you are shooting downward, the shorter the horizontal distance your target is from you.
_________________________
Smokeless Muzzleloading: It ain't your Grampa's flintlock

Top
#2953465 - 09/22/12 11:27 PM Re: Setting CrossBow Scope Questions [Re: Rubberduck270]
cmoses
4 Point


Registered: 02/04/07
Posts: 473
Loc: Cottontown

Offline
[censored] I got a headache reading this
Top
#2953592 - 09/23/12 07:49 AM Re: Setting CrossBow Scope Questions [Re: fairchaser]
soshock1
4 Point


Registered: 08/27/10
Posts: 110
Loc: Columbia, TN

Offline
Rubberduck, now if you could just solve the nation's oil problems we would appreciate it. Great answer! Learned something myself too.
Top
#3177261 - 02/26/13 06:09 PM Re: Setting CrossBow Scope Questions [Re: soshock1]
Crovus
Spike


Registered: 12/25/08
Posts: 48
Loc: Covington tenn

Offline
i cant even spell maf
_________________________
If i see it and its brown I'll shoot towards it

Dont hate me for deer hunting hate me cause Im gonna eat what I kill.

Top
#3208033 - 03/29/13 06:19 PM Re: Setting CrossBow Scope Questions [Re: Crovus]
SCAT
6 Point


Registered: 08/10/12
Posts: 629
Loc: ANDERSON CO.

Offline
Basically, if the shot is less than a 40-45 degree angle you should be ok. Where it really plays a role is when you are shooting straight down and steep angles. During opening week of bow, I shot a coyote that came from behind me. I heard something coming and aimed the crossbow over the side of my ladder stand. The coyote appeared less than 10 feet from my tree. I aimed straight down at the mid portion of its' back and the bolt blew thru its' neck. The only way to prepare for different angles and shots is to practice from your stand, using the exact equipment you will be hunting with. I typically take a cardboard box 1 foot square and 6 inches thick, and fill it with sheets of cardboard and tape it shut. You can use the broadhead over and over, even if it gets dull. It'll still fly the same. Have someone move the box around for you. BTW, the newer rangefinders have angle compensation built in.
_________________________
She told me if I go hunting one more time she's gonna leave me......I'm gonna miss her...

Top
#3208052 - 03/29/13 06:42 PM Re: Setting CrossBow Scope Questions [Re: SCAT]
Frank G
8 Point


Registered: 12/20/12
Posts: 1409
Loc: Hardin Co, TN Pickwick Lake

Offline
Don’t even consider the effect of gravity on a shaft, the calculations are mind-boggling. Best to test sight in your multi reticle. Use a good range finder to set distances from your stand and trust the reticle graduations. I “0” mine at 20, move back to 30 drop one graduation, step back to 40 drop to two below “0” etc out to 50, any further then that is a “crap” shoot unless conditions at perfect. If there is an odd yardage “say” 35 just split the difference and send it. The optic engineers are good at setting up scopes, all manufactures spend $$$$$$$$ getting these correct. I tried a friend’s multi red dot. Don’t bother with one of that design, I’ll take line graduations anytime
_________________________
Team M.I.A.
Captain

Top
Page all of 2 12>


Moderator:  RUGER, Bobby G, Unicam, CBU93, stretch, Kimber45, Mrs.Unicam, Crappie Luck 
Hop to:
Top Posters
4105543
RUGER
87043
Deer Assassin
65411
BSK
61038
Crappie Luck
51376
spitndrum
Newest Members
Mik475, AaronB, Bad Wolf, jw3783, Jesse91
13278 Registered Users
Who's Online
25 registered (MUP, Rockhound, huntncoach, Jeff!, swami, Tn Joe, 2 invisible) and 89 anonymous users online.
Forum Stats
13278 Members
42 Forums
93274 Topics
1089116 Posts

Max Online: 788 @ 11/11/13 08:06 PM
Moon Phase
CURRENT MOON
September
Su M Tu W Th F Sa
1 2 3 4 5 6
7 8 9 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25 26 27
28 29 30
Forum Donations
The TnDeer.Com Deer Talk Forum is for Tennessee Deer Hunters by Tennessee Deer Hunters. If you enjoy using our Talk Forum and would like to contribute to help in it's up-keep. Just submit your contribution by clicking on the DONATE button below and paying with PayPal or a major credit card. Any amount is much appreciated. Thanks for your support!

TN Burn Safe

Generated in 0.105 seconds in which 0.001 seconds were spent on a total of 14 queries. Zlib compression enabled.