If I need a chart to refer to, and the time to refer to it, then the critter is probably too far away for me to shoot at with a familiar hunting rifle..
All very true, but apparently taped on ballistic charts are the rage this year based on this thread. You need to hit Walmart and get with the program.......... Proper paper, tape, etc.
The effort will be far more valuable than actually knowing how your rifle shoots from actually taking time to shoot it.