Angle Cosine Indicator -- Keeps Angled Shots on Target -- The "Angle Cosine Indicator" is an invaluable tool for hunters and varmint shooters in mountainous terrain. A rugged precision instrument, it's crafted from aircraft-grade aluminum, anodized in matte black. The A.C.I. is completely compatible with the "Mil-Dot Master" and ballistic software, as the cosine numbers are in 5-degree increments.
It is simple to use:
1. Get the "angle cosine" number by aiming at the target, then looking at the A.C.I.'s red line. 2. Range the actual sloped distance to target and then multiply that distance by the angle cosine number to get your angle-corrected distance. 3. Adjust the elevation knobs on your scope for the "corrected range". That's it!
For example, if you range the line of sight distance to your target at 400 yards, and the ACI shows a cosine value of 0.87 (for 30 degrees), then your flat-line "gravity-corrected distance" is 400 x 0.87 = 348 yards. Dial your elevation for 350 yards (from your come-up table) and you're good to go.
More Precise Method with Exbal Program The simple multiplication method works well for typical 100-300 yard hunting distances. For longer-range shots, out to 1000 yards, some other factors come into play. The most accurate method for long ranges is to input the cosine number into ballistic software, such as Exbal Ballistic Targeting Software, that runs on a PDA or Palm Pilot. The software takes into account the fact that, during an angled shot, the bullet must still travel the full distance to target, and will have a longer time of flight than when covering the flat line distance. At very long ranges there can be as much as eight (8) MOA difference between the simple multiplication method and the solution generated by the ballistic software.
For more info, visit Sniper Tools or call (800) 651-1050 or (818) 676-0280.