What kind of sighting adjustments are needed when shooting down/up at a target?  Here is why I am asking:

I was out doing some rodent control in a fairly hilly area.  Sometimes I was level with the target, other times I was on a hill about 30' higher than my groundhawg target, and about 30 yards away.  

All shots taken level with target hit, many of the elevated shots went high, even though the distance was about the same.

I was using just a regular old Rugar 10/22 with a 9x scope, sighted in at about 30 yards.  Ammo was Aguila 30 grain Supermax jacketed hollowpoints.  The high velocity stuff (1750fps).

Thanks for the help...

MG

Elevated shots go high because when you take the shot, you form a right triangle with the path of the bullet as the hypotenuse, the altitude (straight verticle line) from your elevation to the target as  leg 1, and a line from your feet perpendicular to the altitude as leg 2.

Scopes are zeroed on level ground to compensate for the effect of gravity over the entire distance of a shot. When you shoot uphill, gravity only effects the bullet for the length of leg 2 of our triangle not the entire shot (hypotenuse).

As an example there is a rabbit 50 meters away from me (slant distance, aka hypotenuse of the triangle), and 30 meters above me (altitude, or leg 1). Leg 2 = 40 meters. If I take the shot compensating for 50 meters, I'll be high because gravity was only effecting the bullet for 40 meters, the length of leg 2.

Ouch! My brain hurts.[:)]

the only way I was able to pay attention in Geo and Science this year was cause I was trying to relate them to shooting ;)

If you are shooting uphill at an extreme angle aim low. If you are shooting downhill at an extreme angle aim low. For an explanation ask the lastboyscout or refer to the Sierra loading manual for an easy explanation.