With long range shooting, History Channel says if you're
shooting up hill (from a valley to hill top), need to aim
high. This, I can understand.

Says if you're shooting down hill, you need to aim lower
than the target. Doesn't make sense.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..

I think you need to aim higher in either case, up hill or down hill.

If you were shooting straight up, distance would not require a change in elevation adjustment, just like straight down.

I shot a deer at 400 yards 4 days ago that was uphill. I hit 5" higher than I wanted [hit the backbone, not the lungs], but it was not because it was uphill. It was due to poor marksmanship.

Refraction due to change in atmospheric density?

I'd figure bullet drop, and need to aim higher. More higher
for farther distance.

Most folks have hit high or low. I've done so little
hunting, I'm not sure I have any stories or experiences with
aim high or low. One time I did shoot a branch out of a
tree, using a deer slug. That was fun.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


wrote in message
news:17265615.1258.1319680704809.JavaMail.geo-discussion-forums@pref15...
I think you need to aim higher in either case, up hill or
down hill.

If you were shooting straight up, distance would not require
a change in elevation adjustment, just like straight down.

I shot a deer at 400 yards 4 days ago that was uphill. I hit
5" higher than I wanted [hit the backbone, not the lungs],
but it was not because it was uphill. It was due to poor
marksmanship.

The History Channel thing mentioned drop. Or lack of drop.
I'm not sure their explaination made sense.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Charles Durrett" wrote in
message
news:2963794.560.1319681421891.JavaMail.geo-discussion-forums@yqbl36...
Refraction due to change in atmospheric density?

On 10/26/2011 8:52 PM, Stormin Mormon wrote:
With long range shooting, History Channel says if you're
shooting up hill (from a valley to hill top), need to aim
high. This, I can understand.

Says if you're shooting down hill, you need to aim lower
than the target. Doesn't make sense.

Actually, when shooting up or down at a steep angle, you have to aim low
to hit your target.

http://www.loadammo.com/Topics/April04.htm

David

That's what I MEANT to say.

Totally fascinating. Thanks for the URL.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"David R. Birch" wrote in message
...
On 10/26/2011 8:52 PM, Stormin Mormon wrote:
With long range shooting, History Channel says if you're
shooting up hill (from a valley to hill top), need to aim
high. This, I can understand.

Says if you're shooting down hill, you need to aim lower
than the target. Doesn't make sense.

Actually, when shooting up or down at a steep angle, you
have to aim low
to hit your target.

http://www.loadammo.com/Topics/April04.htm

David

With no quoted text, it's hard to tell what you meant to
say.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


wrote in message
news:5992969.68.1319684688817.JavaMail.geo-discussion-forums@prng5...
That's what I MEANT to say.

Stormin Mormon wrote:
The History Channel thing mentioned drop. Or lack of drop.
I'm not sure their explaination made sense.

Shooting uphill you're fighting gravity , downhill you're shooting into it
.. If you fired straight down into the gravity well there's be *NO* bullet
drop , LOF would be perfectly straight . Fired perpendicular to the gravity
well , you'll get "X" amount of drop . In between , the drop will vary with
the angle .
--
Snag
Learning keeps
you young !

On 10/26/2011 10:43 PM, Snag wrote:
Stormin Mormon wrote:
The History Channel thing mentioned drop. Or lack of drop.
I'm not sure their explaination made sense.

Shooting uphill you're fighting gravity , downhill you're shooting into it
. If you fired straight down into the gravity well there's be *NO* bullet
drop , LOF would be perfectly straight . Fired perpendicular to the gravity
well , you'll get "X" amount of drop . In between , the drop will vary with
the angle .


I dunno, Snag. If you fired straight down wouldn't it be ALL drop
instead of no drop?

"Snag" on Wed, 26 Oct 2011 22:43:26 -0500 typed
in rec.crafts.metalworking the following:
Stormin Mormon wrote:
The History Channel thing mentioned drop. Or lack of drop.
I'm not sure their explaination made sense.

Shooting uphill you're fighting gravity , downhill you're shooting into it
. If you fired straight down into the gravity well there's be *NO* bullet
drop , LOF would be perfectly straight . Fired perpendicular to the gravity
well , you'll get "X" amount of drop . In between , the drop will vary with
the angle .

Is all vectors.

Bullet "drop" on a perfectly level barrel is 32 ft per second per
second. Shoot from a 32 foot tall tower, and the bullet hits the
ground in 1 second. And so forth
Bullet drop on a barrel angled up is [32 ft per second per second]
minus the upward component of the bullets velocity. E.G. a barrel
aimed at 45 degrees has half the energy going up, and half the energy
going "right", But the energy going up has to overcome gravity, so
each second of flight it has less "up energy", until it reaches zero
and then the bullet starts to descend.
Bullet drop on a barrel angled downward has gravity adding energy
to the downward part of the equation. Stand on the rim of Grand
Canyon, fire downhill at a 45 degree angle, and the bullet now has
half the energy going down, and half the energy going "right", with
gravity adding to the downward motion untill it eventually either is
going "straight down" or it hits bottom.

As most rifles are built with a slight up angle, the bullet is
able to rise for part of the way, before gravity starts it on the
downward path. Sighting in is getting that parabola to be on the
same level as the sights when it reached 100 yards.
But if you are aiming at something one hundred yards "flat
distance" out, but ten yards up or down - for starters, it is not an
even hundred yards to the target. (basic trig) Then start adding in
the downward effect of gravity on the flight of the bullet, and you
miss "low".

At least that's the way it seems to work on paper. B-)


pyotr
--
pyotr
Go not to the Net for answers, for it will tell you Yes and no. And
you are a bloody fool, only an ignorant cretin would even ask the
question, forty two, 47, the second door, and how many blonde lawyers
does it take to change a lightbulb.

On 10/26/2011 11:00 PM, David R. Birch wrote:
On 10/26/2011 8:52 PM, Stormin Mormon wrote:
With long range shooting, History Channel says if you're
shooting up hill (from a valley to hill top), need to aim
high. This, I can understand.

Says if you're shooting down hill, you need to aim lower
than the target. Doesn't make sense.

Actually, when shooting up or down at a steep angle, you have to aim low
to hit your target.

http://www.loadammo.com/Topics/April04.htm

Their diagrams are wrong. Specifically, Fig. 2 shows a much longer
flight path for the "slant range" than for the "horizontal range",
because the former is the hypotenuse of a right triangle, and the
latter, one leg of the triangle. A correct diagram would show an
isosceles triangle, with the two ranges being the same.

As it is, they're comparing apples and oranges, and so their conclusions
are not valid.

On 10/27/2011 2:24 AM, pyotr filipivich wrote:

Bullet "drop" on a perfectly level barrel is 32 ft per second per
second. Shoot from a 32 foot tall tower, and the bullet hits the
ground in 1 second. And so forth

That is incorrect. After one second, it is falling at the rate of 32
feet per second, but it has not fallen 32 feet.

The formula is 2s = gt^2, whe
s is the distance in feet
g is the acceleration of gravity = 32 feet per second per second
t is time in seconds

In one second, an object falls only 16 feet, not 32.

And it takes 1.4 seconds (square root of 2) to fall 32 feet.

[remainder snipped - if you don't have even this much right, I don't
trust the rest of your conclusions]

You can figure it out.

"pyotr filipivich" wrote in message
...
...
At least that's the way it seems to work on paper. B-)

pyotr

Somewhere I read that the drop of a rocket, bomb, bullet etc depends on only
the horizontal component of the distance (actually time of travel) to the
target. A projectile launched vertically will travel in a straight line.

Think of gravity like wind.
When shooting up wind or down wind, there is no adjustment for windage.
But when shooting perpendicular to the wind, there is a maximum of windage adjustment required.

When shooting at an odd angle to the wind, I adjust the windage as the cosine of the angle that my rifle deviates from being pointed across the wind.

So if the 10 mph wind is 15 degrees off being perpendicular to the wind and my Quicktarget program says to correct 20 inches at 300 yards, then I correct Cos(15) 20" = 18.8".


Likewise if I were shooting up hill by 15 degrees and the Quicktarget program said to compensate for 300 yards with 4 moa, then I would compensate by cos(15) 4moa = 3.9 moa.

On Wed, 26 Oct 2011 21:52:10 -0400, "Stormin Mormon"
wrote:

With long range shooting, History Channel says if you're
shooting up hill (from a valley to hill top), need to aim
high. This, I can understand.

Says if you're shooting down hill, you need to aim lower
than the target. Doesn't make sense.

try http://www.exteriorballistics.com/eb...ned/5th/33.cfm for a
good explanation of why.


--
John B.

"Jim Wilkins" on Thu, 27 Oct 2011 08:04:28
-0400 typed in rec.crafts.metalworking the following:

"pyotr filipivich" wrote in message
.. .
...
At least that's the way it seems to work on paper. B-)

pyotr

Somewhere I read that the drop of a rocket, bomb, bullet etc depends on only
the horizontal component of the distance (actually time of travel) to the
target. A projectile launched vertically will travel in a straight line.

As Galileo first demonstrated. an object launched horizontally
will hit the ground at the same time as a similar object dropped.

tschus
pyotr
--
pyotr
Go not to the Net for answers, for it will tell you Yes and no. And
you are a bloody fool, only an ignorant cretin would even ask the
question, forty two, 47, the second door, and how many blonde lawyers
does it take to change a lightbulb.

Doug Miller on Thu, 27 Oct 2011
07:28:21 -0400 typed in rec.crafts.metalworking the following:
On 10/27/2011 2:24 AM, pyotr filipivich wrote:

Bullet "drop" on a perfectly level barrel is 32 ft per second per
second. Shoot from a 32 foot tall tower, and the bullet hits the
ground in 1 second. And so forth

That is incorrect. After one second, it is falling at the rate of 32
feet per second, but it has not fallen 32 feet.

The formula is 2s = gt^2, whe
s is the distance in feet
g is the acceleration of gravity = 32 feet per second per second
t is time in seconds

In one second, an object falls only 16 feet, not 32.

And it takes 1.4 seconds (square root of 2) to fall 32 feet.

[remainder snipped - if you don't have even this much right, I don't
trust the rest of your conclusions]

Sorry, that's a regular braino of mine. Unless I'm actually
working it out on paper, I forget that "minor detail". Andit was the
only numerical example I gave.
--
pyotr
Go not to the Net for answers, for it will tell you Yes and no. And
you are a bloody fool, only an ignorant cretin would even ask the
question, forty two, 47, the second door, and how many blonde lawyers
does it take to change a lightbulb.

On Oct 27, 7:04*am, "Jim Wilkins" wrote:
"pyotr filipivich" wrote in message

...

...
At least that's the way it seems to work on paper. *B-)

pyotr

Somewhere I read that the drop of a rocket, bomb, bullet etc depends on only
the horizontal component of the distance (actually time of travel) to the
target. A projectile launched vertically will travel in a straight line.

This is the correct answer. So you aim high shooting either up OR
down a hill for the slant distance. Book trajectories are only for
cases where the gun and target are on a horizontal plane. If you work
out the force vectors, you can see why.

Stan

On 10/26/2011 6:52 PM, Stormin Mormon wrote:
With long range shooting, History Channel says if you're
shooting up hill (from a valley to hill top), need to aim
high. This, I can understand.

Says if you're shooting down hill, you need to aim lower
than the target. Doesn't make sense.


I hunt, and have always used trig to figure the horizontal distance from
the target elevation (+ or-) given it's apparent distance. Works every
time. Now I own a Leupold Rx ranger that does that automatically.

"T.Alan Kraus" wrote:

On 10/26/2011 6:52 PM, Stormin Mormon wrote:
With long range shooting, History Channel says if you're
shooting up hill (from a valley to hill top), need to aim
high. This, I can understand.

Says if you're shooting down hill, you need to aim lower
than the target. Doesn't make sense.


I hunt, and have always used trig to figure the horizontal distance from
the target elevation (+ or-) given it's apparent distance. Works every
time. Now I own a Leupold Rx ranger that does that automatically.

There are a few smart phone apps that do the calculations and will take
into account things like air temp and humidity if you enter them along
with all the ballistic data you have on the gun and ammo.

Stormin Mormon wrote:
With long range shooting, History Channel says if you're
shooting up hill (from a valley to hill top), need to aim
high. This, I can understand.

Says if you're shooting down hill, you need to aim lower
than the target. Doesn't make sense.

Not lower than the target. Just lower than you would if it was uphill.

Maximum range on level ground is achieved with the barrel at 45 deg from
horizontal.

Max range to higher ground needs the barrel higher than 45 deg, and max
range to lower ground lower than 45 deg.

So whatever the range, the barrel must be at a lower angle for downhill than
it would be for the same range uphill.

For the same range on level ground the barrel would be in the middle. So
downhill just requires that you shoot lower than you would for the same
range on level ground, but you're still aiming above the target.


--

Reply in group, but if emailing add one more
zero, and remove the last word.

On Oct 26, 11:00*pm, "David R. Birch" wrote:
On 10/26/2011 8:52 PM, Stormin Mormon wrote:

With long range shooting, History Channel says if you're
shooting up hill (from a valley to hill top), need to aim
high. This, I can understand.

Says if you're shooting down hill, you need to aim lower
than the target. Doesn't make sense.

Actually, when shooting up or down at a steep angle, you have to aim low
to hit your target.

http://www.loadammo.com/Topics/April04.htm

David

Bingo. We have a winner.

Dan

On Oct 27, 2:36*pm, "Tom Del Rosso" wrote:

Maximum range on level ground is achieved with the barrel at 45 deg from
horizontal.

This is true only in a vacuum. In real life it depends on a bunch of
things. As I remember someone determined that a 30-06 achieved max
range at 36 degrees. But do not take this as gospel. It depends on
the bullet. I think the 36 degrees was for something like a 180 grain
boattail bullet.

Dan

"Jim Wilkins" wrote in message
...

"pyotr filipivich" wrote in message
...
...
At least that's the way it seems to work on paper. B-)

pyotr

Somewhere I read that the drop of a rocket, bomb, bullet etc depends on
only the horizontal component of the distance (actually time of travel) to
the target. A projectile launched vertically will travel in a straight
line.


http://en.wikipedia.org/wiki/Kepler%...anetary_motion

--

wrote in message
...
On Oct 27, 2:36 pm, "Tom Del Rosso" wrote:

Maximum range on level ground is achieved with the barrel at 45 deg from
horizontal.

This is true only in a vacuum. In real life it depends on a bunch of
things. As I remember someone determined that a 30-06 achieved max
range at 36 degrees. But do not take this as gospel. It depends on
the bullet. I think the 36 degrees was for something like a 180 grain
boattail bullet.

Dan

Tests to determine the safety zone behind Army rifle ranges found the
maximum range was nearly constant for elevations between 30 and 40 degrees,
as when firing at towed aerial target. The original 30-06 and the 45-70 both
carry about 3500 yards, a more aerodynamic .30 cal about 5500, and a .50 cal
about 7300. Magnum velocities extend it by only a few hundred yards.

jsw

On Oct 27, 5:40*pm, "Jim Wilkins" wrote:
wrote in message

...
On Oct 27, 2:36 pm, "Tom Del Rosso" wrote:

Maximum range on level ground is achieved with the barrel at 45 deg from
horizontal.

This is true only in a vacuum. *In real life it depends on a bunch of
things. *As I remember someone determined that a 30-06 achieved max
range at 36 degrees. *But do not take this as gospel. *It depends on
the bullet. *I think the 36 degrees was for something like a 180 grain
boattail bullet.

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Dan

Tests to determine the safety zone behind Army rifle ranges found the
maximum range was nearly constant for elevations between 30 and 40 degrees,
as when firing at towed aerial target. The original 30-06 and the 45-70 both
carry about 3500 yards, a more aerodynamic .30 cal about 5500, and a .50 cal
about 7300. Magnum velocities extend it by only a few hundred yards.

jsw

That was what I remembered from something I read some decades ago.
Glad to have someone confirm that my memory still works. The other
thing I remember is that the .22 rimfire does not come close to going
a mile.


Dan

" fired this volley in news:1bb11b1e-
:

That was what I remembered from something I read some decades ago.
Glad to have someone confirm that my memory still works. The other
thing I remember is that the .22 rimfire does not come close to going
a mile.

It's simple, if you think out the 'logic'.

A projectile in a vacuum describes a perfectly parabolic ("ballistic")
flight.

In air, it is slowed by the square (or cube, I don't recall) of it's
velocity because of air resistance.

That means it flys for a while in a nearly ballistic trajectory, then
drops more rapidly. It's sometimes called a "button hook" turn.

The most familiar example is a golf ball driven off the tee. It flies
furthest at a pretty shallow angle. Partly, it's benefitted by lift due
to spin, but mostly it's the effect of air resistance that causes it to
fly fairly straight and long, then just drop out of the air with little
more forward travel.

LLoyd

On 10/27/2011 8:51 PM, Lloyd E. Sponenburgh wrote:
fired this volley in news:1bb11b1e-
:

That was what I remembered from something I read some decades ago.
Glad to have someone confirm that my memory still works. The other
thing I remember is that the .22 rimfire does not come close to going
a mile.

It's simple, if you think out the 'logic'.

A projectile in a vacuum describes a perfectly parabolic ("ballistic")
flight.

In air, it is slowed by the square (or cube, I don't recall) of it's
velocity because of air resistance.


Square...

F=1/2 M V^2



That means it flys for a while in a nearly ballistic trajectory, then
drops more rapidly. It's sometimes called a "button hook" turn.

The most familiar example is a golf ball driven off the tee. It flies
furthest at a pretty shallow angle. Partly, it's benefitted by lift due
to spin, but mostly it's the effect of air resistance that causes it to
fly fairly straight and long, then just drop out of the air with little
more forward travel.

LLoyd

wrote in message
...
- show quoted text -
Tests to determine the safety zone behind Army rifle ranges found the
maximum range was nearly constant for elevations between 30 and 40 degrees,


That is the way it works with a garden hose.

Deer season is on us in earnest. I saw an ad for a deer rifle. It said,
"Rifle has never been strained. Never been fired over 150 yards or uphill."

Friend of mine got a nice 4x4 last Saturday in an area that has more hunters
than trees.

Steve