I do this. Quick 'n dirty chart on the flip up cap using double sided tape.
My detailed chart is on the bottom of my rangefinder. After viewing through the eyepiece, I simply tilt the rangefinder down 45 degrees and there is my chart right in front of my face. Let's face it, if you don't have a rangefinder, you're probably not going to need a detailed drop chart either. I printed out the chart in Excel, then used double sided tape on the bottom, and packaging tape on the top (cut to size) to waterproof it. It's been on there 3 years without coming off at all. The same chart is on my rifle stock so I always have two copies no matter what. Notice the chart is near my face not way down on the butt stock where you have to make an effort to view it while shooting prone if I I decide to use that chart.
