After trying to use a real steel method I found lacking I came up with my own method. I went to a shopping center and found the largest pieces of cardboard I could. I'm talking refridge big. The larger the better. I then used a 8 X 10 piece of printer paper as my standard target. I found the center by drawing a line from corner to corner using a black marker. Then used a tape roll to draw a circle in the center. Took that and printed numerous copies. Oh the circle lines were thick also you want to see them through your scope. Now put you target in the center of the cardboard and move back to whatever distance you prefer. I started at 10 yards and worked back in 10 yard sections until I reached 50 yards. Yes that's only 150 feet but it was just to refine it for now. I don't want to be at 300 feet wondering were the hell the rounds are going. And last fire three rounds before making any adjustments. Make your adjustment then fire three more rounds. either use a spotting scope or bino's if your scope isn't powerful enough.