Shooting uphill vs downhill

Discussion in 'Long Range Hunting & Shooting' started by lefty15, Nov 28, 2008.

  1. lefty15

    lefty15 Well-Known Member

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    I was watching a hunting show on the tube last night, and the host was talking about shooting uphill and downhill.
    The host said that when shooting uphill at say 400 yards it would be like making a 200 yard shot depending on the angle, and the shooter in alot of cases could just shoot straight at the animal, and in some cases maybe even hold under the animal to make the shot. The host the said when shooting downhill depending on the angle the shooter should hold over the animal to make the shot. The host did say that every situation is different, and to use this as just a guidline.
    I know that alot of you have far gretaer knowledge about shooting than I have, so do you think that what the host on that TV show was right with his comments, about uphill and downhill shooting?
     
  2. geargrinder

    geargrinder Well-Known Member

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    The only thing the guy said that was correct was that you need to make corrections for up and down shots.

    It doesn't matter if it is up or down. Gravity only affects the horizontal distance that the bullet travels. It will always be a shorter distance than the distance between the rifle and target.

    This is why we want the cosine angle or cosine factor. You use this to calculate the horizontal distance that the bullet will travel.

    That is about as simple as it can be answered without going into trig and geometric mathematics.

    If you want the nut and bolts of the math and how it all works, ask Eaglet. He loves that stuff.
     

  3. MontanaRifleman

    MontanaRifleman Well-Known Member

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    There is a very good thread on this subject in the Technical Articles Forum. Shooting at angles.

    Basically, the shooting dynamics of shooting up or downhill are the same, in that you are componsating for the horizontal distance traveled and not straight line distance.

    Another thing to consider is the path the bullet will take through the body of the animal. If it's a significant angle upwards, you want the bullet to enter low, in order to pass through the vitals and you want the bullet to enter high when shooting down hill.

    Read the other thread. Some very good articles and links in it.
     
  4. lefty15

    lefty15 Well-Known Member

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    The article in the technical articles is very good. So basically if you are shooting up hill or down hill once you have determined the distance to the target the shooting distance will always be less than what was ranged due to the affect of gravity on the bullet. Does that sound right.
     
  5. Varmint Hunter

    Varmint Hunter Well-Known Member

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    Correct - And the (corrected) distance for holdover can be calculated and corrected for.

    I might add that for a 400 yd shot to be adjusted to a 200 yd hold-over the angle would have to be EXTREME. It would require an uphill or downhill angle of about 60 degrees.
     
  6. Buffalobob

    Buffalobob Writers Guild

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    To summarize the article, here is what it says.

    1. Get the range with your range finder
    2. Get the drops for that range
    3. Get the angle and the cosine of the angle
    4. Multiply the cosine times the DROP (NOT THE RANGE).
    5. Dial in the reduced drop.

    The cosine times the range is not the same as the cosine times the drop.
    We have had agreement on this method for over a year now and there is no reason for anybody to be doing it wrong anymore.

    The question of uphill versus downhill is just a very small difference and is only of interest to those of us who are too lazy to find something more worth while to do. Some ballistic programs will calculate a difference at very long ranges
     
  7. J E Custom

    J E Custom Well-Known Member

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    It is amazing what you see on the tube and read in magazines.

    And he was dead wrong ,As the guys said .

    Kind of like the guy that had his rifle sighted in at 100yrds and said he killed his deer at 600yrds
    by holding at the top of his back.

    You cain't fix stupid

    J E CUSTOM
     
  8. Jared06

    Jared06 Active Member

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    If it's on TV it must be true...... Good reason to just go out and do some practise on targets shooting at differing ranges and angles. There is always knowledge of theory, but equally important is knowledge by experience.
     
  9. yama49

    yama49 Well-Known Member

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    Its only 70 inches of drop with my 338 edge at 600 yards with 100 yard zero. MUST BE BIG DEER THERE... lol
     
  10. jeff 300

    jeff 300 Well-Known Member

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    that's why i hate going into gunshops,archery shops,sporting good store's, gun shows with all of the bull sht you can here or be told by the guys working at them. but it is kind of funny to set back and just lisen in at the start of the season.
     
  11. wbhco2009

    wbhco2009 Member

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    Hi guys and gals.

    this is my first post and yes there is a needed corection when shootoing up hill or downhill. Aim lower due to the following explanation.

    Last fall in British Columbia I took a Mt Goat at 434 yds because I used a TBR rangefinder. Not my longest shoot every but it was the one in the most extreme conditions and slope.
    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.
    [​IMG][SIZE=-2]Leupold RX-III TBR display for example above.
    Illustration courtesy of Leupold & Stevens,Inc.[/SIZE]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.