SILVERTIP-CO

Its easy to remember

if its steep up or sttep down- HOLD LOW

mooseslayer3

i know it depends on the situation but how low would u hold if ur target is like 200 yards down on a steep angle

stubblejumper

That depends entirely on the angle.The steeper the angle,the lower the hold.If for instance you were shooting at a mountaingoat,and the rangefinder read 200 yards to the goat,but the horizontal distance to the goat was only 100 yards,you would aim as if the goat was only 100 yards away.It is basically simple geometry using right triangles.

SILVERTIP-CO

always, hold low nuff said

game4lunch

I disagree with all you "hold it high . . . hold it low" guys. YOU SHOULD ALWAYS PUT YOUR FIRST SHOT ON THE KILL ZONE! Especially at 200 yards. Any modern day caliber has the balistics neccessary and would still be puttin' the shot within' a paper plate uphill or down, especially at 200 yards! You stand a greater chance of missing by creating the uncertainty in your mind by asking, "how much to hold down . . . or up?"
I also am a strong proponent of the high shoulder shot INSTEAD of the "heart/lung" shot. This spot is straight up the front leg, 1/3 down the body from the withers. Puts animals down immediately at any distance.Very ethical kill.Ruins no more meat than a heart/lung.
I do agree that physics dictates bullet trajectoriesWILL get altered depending on raised elevation or lowered elevation, but not enough to start moving your crosshairs around. If you're that uncertain of the shot, you probably shoudn't take it.

stubblejumper

Actually the yardage mentioned was 300 yards which does make a difference.As well the species hunted was not mentioned.In the case of mountain game like sheep or goats you can be 300 yards away from the animal in a straight linebut only 100 yards or soaway horizontally.When you add in the sharp angles present with steep uphill or downhill shots,not taking the actual horizontal distance into account,can result in a wounded animal.

ShatoDavis

Shooters are sometimes confused about the bullets path when shooting uphill or downhill. For instance, does the bullet strike high when shooting downhill and strike low when shooting uphill? Sierra and other bullet companies have done extensive testing on shooting uphill and downhill and have found the following to be true for a given cartridge:
[ol][*]The true vertical bullet drop is the same for level fire and uphill or downhill shooting for the same range. See Figure 1. The vertical drop, do, is the same for all three methods of shooting over the same range.[*]The bullet velocity is the same whether shooting over a level range or shooting uphill or downhill. In other words the bullet does not slow down faster in uphill shooting than with level shooting and the bullet velocity does not increase when shooting downhill.[*]A rifle zeroed in at level range will shoot higher when shooting uphill or downhill. [*]For a given angle of fire the bullet will shoot high by the same amount weather shooting uphill or down hill.

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Fig 1- Bullet trajectories for level fire, shooting uphill, and shooting downhill
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The theory as to why the bullet always shoots high for uphill and downhill shooting is based on the projectiles path in relation to the pull of gravity. Gravity works perpendicular to the horizontal line. It's the horizontal distance traveled by the bullet that is important rather than the actual linear distance traveled. This is explained by the use of trigonometry and the right triangle shown in Fig. 2.
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[blockquote]

Fig. 2-Using trigonometry to explain uphill/downhill shooting
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According to the rules of trigonometry the cosine of THETA is equal to the horizontal range divided by the slant range (hypotenuse). By rearranging the terms, the horizontal range is equal to the slant range (hypotenuse) multiplied by the Cosine of THETA.
Assume we have zeroed a rifle at 300 yd on a level range and we are shooting at a target on a slant range of 300 yards. Assume the slope angle THETA is 30 degrees. The cosine of 30 degrees is 0.87. The horizontal range for the bullet is only 261 yards (300 * 0.87). In order to hit the target we should hold the gun as if the target were only 261 yards away not 300 yards. If we shoot where the scope crosshairs intersect the target we will shoot over the target. In the field, you probably don't really know the slant range or the slant angle very accurately. Just remember to always aim lower, because any slant range shot, either downhill or uphill, will be higher than if it were a horizontal shot.

Our Load From a Disk ballistics program will allow the user to calculate a level range trajectory or enter the slant angle and slant distance and calculate a completely new trajectory for these uphill/downhill conditions.

wyotimberghost

Archers have known this for years. It's all a matter of simple trigonometry.

txhunter58

thanks for the Trig lesson!

MinnFinn

Thanks ShatoDavis, that's the best technical explanation I've seen put down. I've heard varying things over the years. To tell you the truth, hunting in MN there are few times there is that much change in elevation over long distance for it to have significant effect. However, hunting out in the western mountains I know that is a different story.