Shooting high angle targets.......?

[Skychief]

Help settle a little friendly squabble between me and a friend.

I wont bias your response with my take on the following (for now).

'THE GIVEN': You have a rifle sighted dead on a 30 yards. At that range your roundball hits right at the top of your front blade sight.

'THE SCENARIO': It is a beautiful, crisp and clear Autumn morning. You sit atop a fallen log surrounded by mature hardwoods. Your gaze is glued to a huge hollow beech tree (which is 30 yards from your position) surrounded by hickories. It is just a matter of time before the den tree is alive with bright eyed bushytails (squirrels :haha: ) presenting themselves as that evening's main course.
In no time three squirrels are sitting on limb's, next to the trunk, letting the morning sun warm them before foraging in the hickories. One squirrel is 25 feet high. Another is 100 feet high. The last squirrel is way up there....he is at a towering 220 feet high (remember this is a huge beech tree! :wink: )!

'THE QUESTION': Where do you aim to kill each of the squirrels (we can name them...25, 100 and 220 for clarity's sake)?


By the way....you are an absolute crackshot with your frontstuffer! You can and will easily shoot all 3 squirrels in the eye. If, and only if, your sight picture is correct for each at their differing altitudes!

Where do you hold your sights for :

Squirrel (25)....low, right on, or high?
Squirrel (100)...low, right on, or high?
Squirrel (220)...low, right on, or high?


Thanks for weighing in fellers! Skychief. :bow:

 

[roundball]

All upward or downward shooting angles will print high...it's the pure influence of gravity.

Depending on things like velocity, size of the target area on the squirrels in your example, it should be safe to say you could hold dead on #25 and still hit him, slightly higher for #100, and even higher for #220...not possible to determine the amount of holdover from the limited info though.

 

[ohio ramrod]

Actually gravity toward the center of the earth is a constant, The "drop" could be calculated since you have the angles and distant for each shot. All you would need is muzzle velocity and the coefficient for the air resistance and do some vector analysis but I would just use "kentucky windage" and leave the calculating for others.

 

[Skychief]

Alright guys....sounds like you want load stats.

How about a .310 roundball at 2000 f.p.s. at the muzzle.

Target size: a 2" diameter circle (~grey squirrel noggin).


Come on now and fire away with your points of aim on these three hypothetical squackers! :hmm:

 

[longcruise]

Come on now and fire away with your points of aim on these three hypothetical squackers

Your rifle is dead on at 30. Your squirrel tree is 30 yards away. On all three shots gravity will act upon the ball over a 30 yard horizontal distance. It's the horizontal distance of travel that will determine the variations in point of impact. Since there is no variation, all are 30 yard shots as far as bullet drop goes. You aim dead on for all three.

Others who point out that shooting up or down at extreme angles will result in a higher point of impact are correct. But, that concept only applies when calculating your shot based on the actual distance to the target and at the same time in relationship to your sight in range.

For example; your squirrel that is 220 feet up the tree is 73 yards away. Distance to the tree is 30 yards. Shot is at an angle exceeding 45 degrees. Now, if your rifle was sighted dead on at,say, 75 yards, then you would have to aim low for a probable high poi in relation to your poa.

At least that's the way my twisted mind sees it. Could be full a B$ too. :haha:

 

[roundball]

All upward or downward shooting angles will print high...it's the pure influence of gravity.

Depending on things like velocity, size of the target area on the squirrels in your example, it should be safe to say you could hold dead on #25 and still hit him, slightly higher for #100, and even higher for #220...not possible to determine the amount of holdover from the limited info though.

Funny how the subconscious works...out of nowhere last night this thread crowded back into my mind and I recalled that I had made one of my statements backwards...I meant to say 'amount of hold under', not 'amount of hold over'.
With projectiles printing higher for both up or down angles, we have to hold 'under' to compensate, sorry about that...knew what I wanted to say, just said it backwards
:redface:

 

[bigted]

:thumbsup: you are correct sir. the length of the shot meassured over a straight horazontal plane is the yardage you want for dead sight.

the angle is unimportant but the yardage straight to the vertical plane is. gravity is gravity, it never changes. longrange shooting is meassured on a strictly horozontal and tho the angle is there,,,the figured shot for dead reconing is the horozontal not the length of the true shot in yardag.

confusin huh???

 

[Claude Mathis]

All upward or downward shooting angles will print high...it's the pure influence of gravity.

Nuff said. :thumbsup:

 

[Skychief]

Marmotslayer and BigTed, Congratulations! (Sorry Roundball and Claude :haha: )!

Maybe "congratulations" is premature, but, until someone convinces (or shows) me otherwise, I believe each of the three squirrels will be taken with a dead-on hold. No kentucky windage need be involved at all.

Marmotslayer and BigTed did a good job in explaining the "science behind the theory"( :hmm: ).

I have been gauging horizontal distance to the vertical plane of targets for a long time. While it may sound confusing to begin with, it isn't. It is a great aid in shooting.

This may help......If a feller is bowhunting out of a tree 30 feet high with a multiple sight-pinned bow and wants to hit a cocklebur on a deer's hide standing 20 yards from the base of his tree......he will only do so if he uses his 20 yard sight pin. Even though the actual distance between the cocklebur and deer is farther than 20 yards it doesn't matter. The horizontal distance to the targets vertical plane trumps everything else.

I hope others will chime in. I have found this "knowledge" to be a great help in simplifying sight
picture on angled shots. I hope it will help others here too with their hunting/shooting! :thumbsup:

Now watch some Einstein prove me wrong! :rotf:

Skychief :thumbsup:

 

[Skychief]

I should have added....trajectory is trajectory....uphill, downhill (as in the above bowshot example). :hatsoff:

 

[necchi]

I believe each of the three squirrels will be taken with a dead-on hold. No kentucky windage need be involved at all.

In this case I believe your right, but only because of your example of 30yrd zero and the ballistics of the small cal RB. The ball will drop enough at the described distances to comp for the "high" sighting plane of the angled shot.
The dynamics change alot when you start talkin flat shooting high BC projectiles.

 

[roundball]

Well, let me try this...

When a rifle is sighted in on the horizontal, the sights are adjusted to offset the effects of gravity force which is being applied straight down on top of the projectile causing deflection of the projectile downward...the effects of gravity on the horizontal is maximum when it acts upon a projectile at 90 degrees.

Then when you shoot at any angle up or down relative to that horizontal, less and less effects of gravity are being applied to the projectile, it'll have less deflection, and it'll print higher in both cases because of the sight settings.

Think of it like this...if we shoot straight up into the air with gravity right on the nose of the projectile there would be no gravity deflection...but at any other angle than vertical, the effects of gravity deflection come into play, becoming maximum when the projectile is traveling on the horizontal...and less at any angle otherwise as the path of the shot approaches vertical again, either up or down vertical.

===========================================
UPDATE: Here's the official explanation:
http://www.exteriorballistics.com/ebexplained/5th/30.cfm

“”¦..Shooting uphill or downhill also causes significant changes to the trajectory of a flying bullet compared with its trajectory on a level firing range. In fact, if a gun is sighted in on a level range, a bullet fired either uphill or downhill always shoots high relative to the shooter’s line of sight through the gun sights. Two effects contribute to the trajectory changes. One is geometrical, and we will describe this effect in a later subsection. The other is the fact that when a bullet travels upward or downward relative to the firing point, the density of the air changes, affecting the drag. These trajectory changes also are computed in Sierra’s Infinity program”¦..”

 

[Skychief]

Roundball, I read the above. The ball will indeed rise above the line of sight at angled shots. It also does this on horizontal shots.

Do you guys have any nuts on the hickories in North Carolina this year? If so....

Find one where you can safely shoot into it's crown. Take an accurate rifle (22 with shorts, your favorite flinter, 45/70, whatever). Make sure that the rifle is accurate for this exercise. It needs to wear open iron sights, peep sights, scope.....(in other words, type of sight matters not).

Know the zeroed range of said rifle. 10 yards is fine, 30 yards is fine, 50 yards is fine. In other words...any zero (Horizontal) is fine so long as it is known.

Set up the known zero range away from the tree's trunk. Pick out some nuts that are near to the trunk's vertical plane ( in other words, don't pick on nuts that are on the near or far side of the crown if the crown is really big). If they are 10 feet high, great! If they are 50 feet high, great! If they are 150 feet high, super! It does not matter how high they are, so long as you are the rifle's know zero range away from the trunk of the tree.

Open fire with no holding under nor over and enjoy the afternoon. Please remember to leave some for the squirrels! :rotf:

Respectfully submitted, Skychief :haha:

 

[Skychief]

Where in the devil is PaulV when ya need him? :rotf: :rotf: :haha: :shocked2:

 

[tg]

The distance for effective sighting will be the same on all three as that is the distance from you to the tree and the distance gravity has to effect the ball.The base of the triangle will be your "range" regardless of the distance of the hypotenuse.

 

[runnin lead]

Also consider the angle of impact & bullet path of travel after impact.
If on a steep angled shot at a deer at an upward
angle a shot aimed at the heart would by the time it penetrated as far as the heart be over the heart & into the lungs , using the same aimpoint on a rather extreme angle downward shot the bullet path would pass beneath the heart.

 

[paulvallandigham]

I tire of you as the emcee. You have received excellent answers, and I have no need to add to them.

 

[roundball]

You're changing the landscape a little...in my first reply the jist of the hypothetical seemed oriented towards the question of rise or fall of a shot.

And I added that lacking details like caliber and velocity to actually do calulations, the hypothetical could not allow anyone to actually claim if a point blank hold could be used.

Then you added more criteria...and now we're talking about .22 rifles and nuts in a tree :grin:



In summary, I stated the facts surrounding bullet rise on angles, as they exist in exterior ballistics, and will stick with those proven forces of work, along with Sierra, et al.

( going out with a .22cal shooting at nuts on a tree ???...I'll leave such activities to you :grin: )

 

[roundball]

trajectory is trajectory....uphill, downhill

If by that you mean trajectory is the same regardless if the shot is horizontal or angled up or down...that's not correct. Gravity is different on the different shots.

 

[Claude Mathis]

Here, let me repeat this so people don't get confused by all the theories being tossed around.

All upward or downward shooting angles will print high...it's the pure influence of gravity.

Nuff said. :thumbsup: