Shooting at deer downhill question

[Ajj828]

Where I hunt it's very steep and hilly there is almost no area with flat ground. I sighted in my rifle at roughly 70 yards (I plan to go to a range before hunting season and make sure it truly is a 100 yard zero). I'm assuming most of my shots will be at a good steep angle either downhill or up hill. When shooting uphill and down hill do you have to hold your crosshairs high or low? Or do you just aim exactly where you want to hit the deer? Is it true that shooting downhill makes a flatter shot? This is my first year using a rifle so I'm not sure how rifles really shoot when it comes to elevation. I plan on going out and shooting on steep areas to test later in the summer.

[ghosthunter]

Under 100 yards the adjustment is minimal. Just aim a little low. Up or down.

Over 100 yards a little more calculation is involved,depending on bullet and load.
There is no replacement for actual practice.

Read here.


http://millettsights.com/downloads/ShootingUphillAndDownhill.pdf

[dreamunelk]

What caliber?  Scope?  You may want to consider a 200 yard zero.  What distances do you think you will be shooting?

http://www.chuckhawks.com/shooting_uphill.htm

Do a search on sighting in.  Lots of info out there.

A range finder that shows true ballistic range in very helpful.

Most important practice a lot!

[Ajj828]

What caliber?  Scope?  You may want to consider a 200 yard zero.  What distances do you think you will be shooting?

http://www.chuckhawks.com/shooting_uphill.htm

Do a search on sighting in.  Lots of info out there.

A range finder that shows true ballistic range in very helpful.

Most important practice a lot!

Tikka t3x 30-06 with a leupold vx2 4-12 50mm. I am for sure going to get myself a range finder this season. From the area I'm scouting I could easily get a 150-200 yard shot. I can't see myself getting very close to the deer like within 100 yards. I will also be looking down hill into some clear cuts so maybe 150-200 yard downhill shots. I'm using 180 grain bullets. I can't seem to find a place to sight my gun in at 200 yards. All the legal target shooting areas are 100 yards or less. I'll have to see if any local ranges have 200 yards

[Tbar]

Aj, don't over think all of this.  Your setup is capable of all the ranges you mentioned.  If you are not going to be shooting beyond 300-350 you do not need a range finder. Your key to knowing what the ranges are will be learned at the range.  Practice! Practice! Practice!  Where are you located?

[Bob33]

Up to 200 yards don't worry about. If you shot at a 45 degree angle at 200 yards the drop would be about the same as a shot on level ground at 140 yards. You'll mess yourself up trying to compensate worse than not doing so at those distances on big game. Sight your gun in to hit 2 inches high at 100 yards and hold dead on out to about 250 yards.

[jay.sharkbait]

30/300

If it's less than 300 yd and or 30deg don't sweat it.

[Magnum_Willys]

A 20 degree hill up or down is really steep.   You wouldnt think so until you put an inclinometer - rangefinder on it.  A 20 degree hill subtract 6% from your distance.   I.e  400 yards down/uphill = 376 yards.

Not that big a deal usually. Like said above 30/300 ....

[Ajj828]

Aj, don't over think all of this.  Your setup is capable of all the ranges you mentioned.  If you are not going to be shooting beyond 300-350 you do not need a range finder. Your key to knowing what the ranges are will be learned at the range.  Practice! Practice! Practice!  Where are you located?

I think I am over thinking it. I'm just going to use a 100 yard zero and then practice 150-175 yard shots. I'm from SW Washington

[jay.sharkbait]

Some high incline training we do at Bull Hill.

[Bob33]

Aj, don't over think all of this.  Your setup is capable of all the ranges you mentioned.  If you are not going to be shooting beyond 300-350 you do not need a range finder. Your key to knowing what the ranges are will be learned at the range.  Practice! Practice! Practice!  Where are you located?

I think I am over thinking it. I'm just going to use a 100 yard zero and then practice 150-175 yard shots. I'm from SW Washington

You would be better off sighting in 2 inches high at 100 yards. That way you will be plus or minus 2 inches out to about 230 yards. With a 100 yard zero you will be 4 inches low at 200 yard and 6 inches low at 225 yards.

[KFhunter]

For live game you also need to consider bullet travel path through the target especially on extreme angles.   Shooting down you'll want the bullet to hit higher on the deer travelling down through the heart and exiting low, the opposite is true for uphill shooting.


 

[brew]

totally agree with the last 2 posts...sight in 2" high at 100 and that will put you about dead on at 200...on steep shots you want to aim not where you want to hit on the fore side of the animal but where the bullet will exit on the aft (back) side of the animal.  with 3" of  "play" up to around 250 yards it shouldn't matter that much as long as you aim for where the buttet is going to end up rather than where the bullet hits.  my last bear was a steep down angle quartering towards my left so i put that 160 gr nosler partition high in his neck angling behind his off shoulder and he hit the ground like the carpet was pulled out from under him

[yakimanoob]

The key points have been well covered.  If you only plan to shoot out to 200-ish yds, you have nothing to worry about.  Your 180gr bullets from a 30/06 will be travelling so fast at that range you've got nothing to worry about.  And I'll echo the previous comment that it's VERY easy to WAY over-estimate inclines in the field.  (Just think about how many fish stories you've heard about people climbing up 50-60 degree hills to get where they were).  30 degrees is quite steep and you're unlikely to encounter a higher angle than that. 

But if you're curious, the math in concept is quite simple.  From the reference of your crosshairs, your bullet will always (regardless of caliber, bullet design, muzzle velocity, air density, etc.) fall a distance (d) equal to the square of the time (t) the bullet spends traveling, times the acceleration due to gravity (g), all divided by two. In other words,  d = 0.5*g*t^2 .

If you're shooting at an angle, the acceleration due to gravity changes according to the cosine function - so if you're shooting at 30 degrees, which again is an extreme angle, the acceleration due to gravity is reduced by about 13%.  If you're shooting up (or down), gravity will slow (or speed up, respectively) your bullet according to the sine function.  So if you're shooting down at 30 degrees, your bullet will accelerate towards your target at 50% the force of gravity, or 16 feet per second squared.  This reduces your flight time and thus your bullet drops a shorter distance according to the formula above.  If you're shooting up at the same angle, your bullet will decelerate at the same rate, lengthening your flight time and thus increasing your drop. 

Simple enough in concept.  But that pesky little flight time value is a B*%CH to figure out as it depends on everything (caliber, bullet weight, air density, bullet design, muzzle velocity, etc.) and requires calculus, which is why we have ballistics calculators. 

So at the end of the day, if your shooting a 180gr bullet with a BC of .507 from a 30-06 leaving your barrel at 2750fps (standard velocity according to Nosler for their 180gr partition ammo), and you're shooting down at 30 degrees at a range of 200yds, Hornady's ballistics calculator says you'll hit 1.4 inches higher than you would if you were shooting across flat ground.  At 300yds range, that error goes up to a whopping 3.3 inches. 

QED. Ignore the math if you're shooting less than 300yds. 

[Magnum_Willys]

Its not that complicated - on phone calculator press type incline in degrees, press "cos" button, times yards.  Done.