Brent... Let me see if I can shine some light on what’s really going on when you shoot on an incline or decline.
When you zero your rifle, (lets say that you zero it at 100 yards and you are shooting flat). Because you are shooting “flat”, (meaning not on an incline or decline), you have the full effects or force of Gravity pushing downward on the bullet. So when you zero, you have adjusted the sight height above the bore, so the bullet leaves the barrel, arcs up into the full force of gravity and then drops down onto the bulls-eye.
When you shoot at an incline or decline (Angled Shooting) the effects or force of gravity is less; but you still have the same sight height above the rifles bore.
This means that the bullet is leaving the rifle’s bore, theoretically but not specifically on the same arc. This is why the bullet hits high; and a knowledgeable shooter will correct for the “gravity” distance to target. The Cosine method of calculation works very, very well for small arms fire and is the method taught in most if not all military and OGA’s precision shooting classes.
The cosine method of calculating will give you the bottom leg of the triangle. (Please read the article on my web site.)
To use the Angle Cosine Indicator is relatively simple and works like this:
1) Acquire the straight line distance to target.
2) Aim at the target and acquire the cosine number of the angle that you are holding at by looking off to the side of your scope at the Angle Cosine Indicator.
3) Multiply the cosine number to the previously acquired straight line distance to target. (.7 x 500 yards = 350 yards) or input the angle into your software.
4) Look at your data card for your hold or moa adjustment.
5) Make your adjustment and fire on the target.
As you can see, it is pretty simple.
Sniper Tools Design Company
[ 11-18-2003: Message edited by: W ]