shooting down hill high bullet
- Thread starter COYKILL
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NdIndy
New member
Nope, uphill/downhill/whatever doesn't affect your bullets path. Physics doesn't change depending on which direction you're facing. Shooting high is a result of aiming high.
The problem/reason people over shoot is they aim for the visual distance, not the actual distance. The arc of the bullet is defined by the amount of time in flight and the horizontal distance traveled. If your target is up/downhill the visual distance is longer so people tend to overshoot. If you aim for the horizontal distance instead, you hit on target as ever.
The longer the range, the greater the visual difference, the more important actual ranging is.
The problem/reason people over shoot is they aim for the visual distance, not the actual distance. The arc of the bullet is defined by the amount of time in flight and the horizontal distance traveled. If your target is up/downhill the visual distance is longer so people tend to overshoot. If you aim for the horizontal distance instead, you hit on target as ever.
The longer the range, the greater the visual difference, the more important actual ranging is.
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skinney
Director
Originally Posted By: NdIndyNope, uphill/downhill/whatever doesn't affect your bullets path. Physics doesn't change depending on which direction you're facing. Shooting high is a result of aiming high.
i beg to differ... if you are shooting on a level surface, gravity is pulling your round directly away from the LOS... Shooting up or down hill your LOS is "elevated" up or down, gravity is still pulling your bullet straight down, which is no longer "directly" away from your LOS... it's actually pulling toward or away from your LOS if you look @ an angular diagram shooting up or down hill... SO, when shooting up or down hill there is actually less gravity affecting your bullet causing a high impact regardless if you are shooting up or down... here is an example... 308 @ 1000yds going 3K fps: 0 degree angle = -310" of drop, same scenario with a +45 degree angle = -219", and yet a minor difference with a -45 degree angle = -211".
an angle cosine indicator is your friend.
i beg to differ... if you are shooting on a level surface, gravity is pulling your round directly away from the LOS... Shooting up or down hill your LOS is "elevated" up or down, gravity is still pulling your bullet straight down, which is no longer "directly" away from your LOS... it's actually pulling toward or away from your LOS if you look @ an angular diagram shooting up or down hill... SO, when shooting up or down hill there is actually less gravity affecting your bullet causing a high impact regardless if you are shooting up or down... here is an example... 308 @ 1000yds going 3K fps: 0 degree angle = -310" of drop, same scenario with a +45 degree angle = -219", and yet a minor difference with a -45 degree angle = -211".
an angle cosine indicator is your friend.
Orneryolfart357
New member
Taking this a degree further in the aiming of uphill, down hill, side angle shots. What about shooting on the side of a hill? As an archer we would usually use the trees as a guideline. Trees grow straight up, and aligning the bow with the trees made for better shots. Do rifle shooters do this? If the rifle/Bow is canted, the shot could be off. Interesting thread.
NdIndy
New member
I dissagree with your dissagreement.
But only because you're talking Los, I'm talking trajectory. Ignoring the scope, the bullet is going to have the same poi for the same horizontal range regardless of vertical range.
Take any round, dead on at 100 and raise the target 25 yards straight up. Los is going to be the long side of the triangle. Making up a number, 120 yards. Adjust poa for 120 and you'll hit high, the true ballistic range is still 100 yards. Keep poa at100 and still dead on regardless of angle.
We're just talking different sides of the same coin.
Fortunately in big game hunting we can ignore this in all but extreme cases since the pbr is fairly forgiving. I'm not going to be playing angles and breaking out the calculator with the cos/sin function in any case. Just mentally move the animal to level ground, estimate that range, pull the trigger and start field dressing.
Take any round, dead on at 100 and raise the target 25 yards straight up. Los is going to be the long side of the triangle. Making up a number, 120 yards. Adjust poa for 120 and you'll hit high, the true ballistic range is still 100 yards. Keep poa at100 and still dead on regardless of angle.
We're just talking different sides of the same coin.
Fortunately in big game hunting we can ignore this in all but extreme cases since the pbr is fairly forgiving. I'm not going to be playing angles and breaking out the calculator with the cos/sin function in any case. Just mentally move the animal to level ground, estimate that range, pull the trigger and start field dressing.
Smokeless
New member
Originally Posted By: pahntr760http://www.chuckhawks.com/shooting_uphill.htm
http://www.firearmssite.com/shoot_uphill.htm
This is spot on the money! It is not about LOS in up or down hill shooting it's about the horizontal distance. When you look up or down at any major degree of angle, think of a pie piece or corner of a square in terms of level distance, not the angle or line of site.
http://www.firearmssite.com/shoot_uphill.htm
This is spot on the money! It is not about LOS in up or down hill shooting it's about the horizontal distance. When you look up or down at any major degree of angle, think of a pie piece or corner of a square in terms of level distance, not the angle or line of site.
skinney
Director
Originally Posted By: NdIndy
Fortunately in big game hunting we can ignore this in all but extreme cases since the pbr is fairly forgiving. I'm not going to be playing angles and breaking out the calculator with the cos/sin function in any case. Just mentally move the animal to level ground, estimate that range, pull the trigger and start field dressing.
yes i agree most the point blank range will cover the hunters comfort zone, even shooting in "most" up hill or down hill scenarios, in extreme cases of up and down hill shooting there is even more to take into consideration when "trying" to hit your target, such as altitude change, and the air density along with it... now this is where it becomes fun.
Fortunately in big game hunting we can ignore this in all but extreme cases since the pbr is fairly forgiving. I'm not going to be playing angles and breaking out the calculator with the cos/sin function in any case. Just mentally move the animal to level ground, estimate that range, pull the trigger and start field dressing.
yes i agree most the point blank range will cover the hunters comfort zone, even shooting in "most" up hill or down hill scenarios, in extreme cases of up and down hill shooting there is even more to take into consideration when "trying" to hit your target, such as altitude change, and the air density along with it... now this is where it becomes fun.
Evil_Lurker
New member
Shoot straight up and see if your bullet follows your predicted path.
BuckeyeSpecial
New member
Read up on it in the reloading manuals
http://www.chuckhawks.com/shooting_uphill.htm
Shooting Uphill and Downhill
By Chuck Hawks
The hoary old question of where to aim when shooting up or down hill regularly rears its head. It seems that many hunters understand that shooting at a steep angle changes the point of impact, but can't remember why or in which direction.
The correct answer is to hold lower than normal when shooting steeply up or down hill at long range. (At gentle angles you can ignore the problem altogether over the maximum point blank ranges of hunting rifle cartridges.)
This seems odd to many, and they insist on making the problem more difficult than it needs to be. But the reason is simple. Trajectory, the bullet's flight path, depends on the horizontal (level) range to the plane of the target, not the line of sight range up or down hill. Your eye sees the line of sight (slant) range from your position to the target, which is longer than the horizontal range.
Remember that it is gravity working on the bullet during its flight time that causes it to drop. If you were to shoot straight down, say from a tethered balloon, the bullet would have no curved trajectory, it would travel toward the earth in a straight line, just as if you simply dropped it. Likewise, if you shoot straight up, the bullet travels up in a straight line until its momentum is expended. Again, there is no curved trajectory.
You can infer from this that the farther from the level position a rifle is held when a bullet is fired, the less the bullet's drop will be over any given line of sight distance, whether it is fired up or down. Since your sights are set to compensate for bullet drop, and there is less bullet drop when shooting at an up or down angle, you must hold lower than normal to maintain the desired point of impact. For example, if you are shooting up or down at a 40 degree angle and the line of sight range is 400 yards to the target, the horizontal range is only 335 yards. 335 yards is the distance for which you must hold.
Leupold RX-III TBR display
Leupold RX-III TBR display for example above.
Illustration courtesy of Leupold & Stevens,Inc.
The Leupold RX-III rangefinder that I reviewed for Guns and Shooting Online includes among its many features a mode that automatically compensates for up and down angle shots. Leupold calls this "true ballistic range" and you can set the RX-III's main readout to display the horizontal distance to the target, which is the distance you need to worry about in terms of trajectory. In the lower left corner of the display it also tells you the angle at which your are ranging and the line of sight range from your position to the target.
For example, if I range the top of a tall fir tree some distance from my house the line of sight range is 151 yards and the angle is 19 degrees of elevation, while the horizontal range--the true ballistic range--is only 130 yards. It is a neat rangefinder and a little time spent with one drives home the reality that, in terms of bullet trajectory, it is the horizontal, not the line of sight, range that matters.
==================================
======================================================================================
This is the way it works.
Any other is BS.
You can not make it any plainer that that.
DAB
Shooting Uphill and Downhill
By Chuck Hawks
The hoary old question of where to aim when shooting up or down hill regularly rears its head. It seems that many hunters understand that shooting at a steep angle changes the point of impact, but can't remember why or in which direction.
The correct answer is to hold lower than normal when shooting steeply up or down hill at long range. (At gentle angles you can ignore the problem altogether over the maximum point blank ranges of hunting rifle cartridges.)
This seems odd to many, and they insist on making the problem more difficult than it needs to be. But the reason is simple. Trajectory, the bullet's flight path, depends on the horizontal (level) range to the plane of the target, not the line of sight range up or down hill. Your eye sees the line of sight (slant) range from your position to the target, which is longer than the horizontal range.
Remember that it is gravity working on the bullet during its flight time that causes it to drop. If you were to shoot straight down, say from a tethered balloon, the bullet would have no curved trajectory, it would travel toward the earth in a straight line, just as if you simply dropped it. Likewise, if you shoot straight up, the bullet travels up in a straight line until its momentum is expended. Again, there is no curved trajectory.
You can infer from this that the farther from the level position a rifle is held when a bullet is fired, the less the bullet's drop will be over any given line of sight distance, whether it is fired up or down. Since your sights are set to compensate for bullet drop, and there is less bullet drop when shooting at an up or down angle, you must hold lower than normal to maintain the desired point of impact. For example, if you are shooting up or down at a 40 degree angle and the line of sight range is 400 yards to the target, the horizontal range is only 335 yards. 335 yards is the distance for which you must hold.
Leupold RX-III TBR display
Leupold RX-III TBR display for example above.
Illustration courtesy of Leupold & Stevens,Inc.
The Leupold RX-III rangefinder that I reviewed for Guns and Shooting Online includes among its many features a mode that automatically compensates for up and down angle shots. Leupold calls this "true ballistic range" and you can set the RX-III's main readout to display the horizontal distance to the target, which is the distance you need to worry about in terms of trajectory. In the lower left corner of the display it also tells you the angle at which your are ranging and the line of sight range from your position to the target.
For example, if I range the top of a tall fir tree some distance from my house the line of sight range is 151 yards and the angle is 19 degrees of elevation, while the horizontal range--the true ballistic range--is only 130 yards. It is a neat rangefinder and a little time spent with one drives home the reality that, in terms of bullet trajectory, it is the horizontal, not the line of sight, range that matters.
==================================
======================================================================================
This is the way it works.
Any other is BS.
You can not make it any plainer that that.
DAB
Last edited by a moderator:
NdIndy
New member
I didn't find an rlf, the crf series doesn't do the correction as far as I can tell.
It's really not that big a deal unless you've got quite a bit of angle or a really long shot. We've been droppng animals forever without any rangefinder at all. Of course ymmv, I mean people in nebraska think a speedbump is mount everest
Just figure if it's a big slope and you aim dead on, you're actually aiming high. Aim high, miss high. The bullet doesn't care and will do exatly the same thing no matter how high or low you point the gun. its just how you perceive what the bullet will be doing that has to be adjusted. Same as when someone finally learns what a bullet and its trajectory normally is and when they learn mpbr for hunting. It clicks.
It's really not that big a deal unless you've got quite a bit of angle or a really long shot. We've been droppng animals forever without any rangefinder at all. Of course ymmv, I mean people in nebraska think a speedbump is mount everest
Just figure if it's a big slope and you aim dead on, you're actually aiming high. Aim high, miss high. The bullet doesn't care and will do exatly the same thing no matter how high or low you point the gun. its just how you perceive what the bullet will be doing that has to be adjusted. Same as when someone finally learns what a bullet and its trajectory normally is and when they learn mpbr for hunting. It clicks.