Posted 19 December 2010 - 09:47 AM
To make trajectory maps for my springer air rifles, I tape a target with multiple 1 inch bullseyes on a cardboard box and shoot a 3 shot group off my knee (to simulate field conditions) every 5 yards from 10 to 50 yards. Then I type it up listing the pellet, the variable scope's preferred magnification setting at which the trajectory was determined (e.g., 9x), list the yards and number of inches above or below the center of each bullseye where point of impact occurred at each yardage. I tape it to the rifle stock using Scotch tape across the whole map to waterproof/dustproof it. Easily removable without damaging the stock. Sometimes if I need to make a field expedient trajectory map, I'll write up a basic trajectory map showing how much holdover or holdunder is required at 10, 25, 35, 40 and 50 yards on a piece of blue tape with a Sharpie and stick it on the stock butt. Again, easy to remove without leaving goo on the stock. Even though it's time consuming, I've found it's much more accurate to make a real life map for your rifle and pellet of choice than rely on the trajectories determined by ballistics programs which just haven't been very accurate for my pellet rifles.