Uphill Shots
10-25-2002, 06:09 PM
#1
Thread Starter
Join Date: Feb 2003
Location: Hico, WV USA
Posts: 393
Uphill Shots
I have a question about shot distance....today I had a really nice gobbler come in behind me and present an uphill shot that was roughly 20 yards. I was up a tree about 20 ft. and the gobbler was actually above me....the hill is quite steep. Needless to say, I shot and missed...short. I recall reading somewhere that there was some kind of equation for figuring out the way that inclines affect a shot....is this so?
Any insight is appreciated!
Any insight is appreciated!
10-25-2002, 08:30 PM
#2
Nontypical Buck
Join Date: Feb 2003
Location: Montgomery IL USA
Posts: 1,231
RE: Uphill Shots
In a nutshell; gravity only effects the arrow over the horizontal distance. That is to say that if, for example...you are hunting flat ground, 30' up in a tree, and a deer is 20 yards from the BASE of the tree...aim 20 yards, not the actual distance from you to the target (which is about 22.4 yards).
The greater the difference between you and the target (or animal), the more yardage you have to deduct from the distance between you and the target to make the shot.
Geometrically speaking, it's called the Pythagorean Theorum (sp?). "A squared" plus "B squared" equals "C squared". I'd suggest plugging "geometry" into an internet search engine for a site that'll show diagrams of how the formula works. It'll help visualize it better.
JRW
The greater the difference between you and the target (or animal), the more yardage you have to deduct from the distance between you and the target to make the shot.
Geometrically speaking, it's called the Pythagorean Theorum (sp?). "A squared" plus "B squared" equals "C squared". I'd suggest plugging "geometry" into an internet search engine for a site that'll show diagrams of how the formula works. It'll help visualize it better.
JRW
10-25-2002, 09:26 PM
#3
Thread Starter
Join Date: Feb 2003
Location: Hico, WV USA
Posts: 393
RE: Uphill Shots
JRW-
Thanks.....high school geometry seems so long ago. I had forgotten about Pythagorean....and it explains why I hit low...I probably compounded it by misjudging by a yard or two.
Appreciate it.
Thanks.....high school geometry seems so long ago. I had forgotten about Pythagorean....and it explains why I hit low...I probably compounded it by misjudging by a yard or two.
Appreciate it.
10-25-2002, 09:59 PM
#4
Fork Horn
Join Date: Feb 2003
Location: Goodyear AZ US
Posts: 215
RE: Uphill Shots
If you download thearcheryprogram and input all your data you can look at a shot replicator that shows elevated and depressed shot angles.
Or you can look at it this way. When you shoot a fixed pin site on level ground at the target 20 yds away you are lofting the arrow to get it to the spot. The amount of loft for your 20 yd shot depends mostly on the speed of your arrow. As soon as the arrow clears the bow gravity starts pulling it to the ground and on a level shot this pull is perfectly perpendicular to the flight path of the arrow so the trajectory of the arrow receives the "FULL" effect of gravity. The arrow is going essentially straight and level and gravity is pulling straight down.
Now if you get up in your treestand and point your bow down at a depressed angle for a 20yd shot (when I say 20yd shot I mean the distance from your front foot to the target, same as the level shot) if you use the same 20yd pin and hold spot on your arrow will hit high. This is because gravity is no longer pulling perfectly perpendicular to the flight path of the arrow. The arrow is getting the same amount of loft it got for the level shot but the flight path of the arrow is at a downward angle. Gravity still pulls the same but since the flight path of the arrow isnt perfectly perpendicular (like the level shot) to gravity's pull the arrows trajectory only recieves a "partial" effect of gravity's pull. In short the arrow doesnt drop as much when you shoot it downhill or uphill for that matter. Like I said in the beginning, this assumes your shot ranges are the same distance and you're using a fixed pin site (not a pendulum).
I imagine there are some formulas out there for gnats assing this stuff but during hunting situations I'm judging distance with my eyes and calculating arrow drop based on how depressed the shot is so a calculator wouldnt do me any good in the treestand. I think thearcheryprogram will give you the most exact answer.
Cargo
Or you can look at it this way. When you shoot a fixed pin site on level ground at the target 20 yds away you are lofting the arrow to get it to the spot. The amount of loft for your 20 yd shot depends mostly on the speed of your arrow. As soon as the arrow clears the bow gravity starts pulling it to the ground and on a level shot this pull is perfectly perpendicular to the flight path of the arrow so the trajectory of the arrow receives the "FULL" effect of gravity. The arrow is going essentially straight and level and gravity is pulling straight down.
Now if you get up in your treestand and point your bow down at a depressed angle for a 20yd shot (when I say 20yd shot I mean the distance from your front foot to the target, same as the level shot) if you use the same 20yd pin and hold spot on your arrow will hit high. This is because gravity is no longer pulling perfectly perpendicular to the flight path of the arrow. The arrow is getting the same amount of loft it got for the level shot but the flight path of the arrow is at a downward angle. Gravity still pulls the same but since the flight path of the arrow isnt perfectly perpendicular (like the level shot) to gravity's pull the arrows trajectory only recieves a "partial" effect of gravity's pull. In short the arrow doesnt drop as much when you shoot it downhill or uphill for that matter. Like I said in the beginning, this assumes your shot ranges are the same distance and you're using a fixed pin site (not a pendulum).
I imagine there are some formulas out there for gnats assing this stuff but during hunting situations I'm judging distance with my eyes and calculating arrow drop based on how depressed the shot is so a calculator wouldnt do me any good in the treestand. I think thearcheryprogram will give you the most exact answer.
Cargo
