Here is a handy little program to calculate standard deviation if you forgot to reset your chronograph. However the program was designed for running standard deviation on large sample sizes where many of the items have the same value. If you happen to separate bullets, cases. 22RF or anything by weight and would like to have the standard deviation using the all the items used in the separation, this program is just what you have been looking for. Entering the data for each item would take forever. So referring to the example screen above, 7918 items were separated by weight in 0.1 grain increments. The weight and number in each weight group is entered and the final standard deviation is listed. The printed graph will also have the standard deviation and total population size printed on the graph.