Re: Do you use an Angle Cosine Indicator (ACI) for uphill/downhill shots?
While the ACI's are still a little spendy and the rangefinder combos are subject to a
possible battery failure. I bought a surveyors inclinometer several years ago to read
in degrees the up and down of places I hunted in. Of course you have to have a ballistic chart, range finding device and windage meter to adjust your sight.
Along with hours and hours of practice to become accurate.
With all that being said, probably quicker and cheaper to just buy an ACI.