Guys, I guess this is the math guy talking here. But what is wrong with knowing the facts? Everytime I see a guy that doesn't grasp a concept with math or anything, they downplay it, and say "screw it, you don't need it". There is nothing wrong with being a little more smarter. I agree that with shooting, usually the sample size isn't large enough to worry about SD, but handloader1 asked a good question, that he didn't know. Getting on here, basically saying "don't worry about it", doesn't help him and is pretty negitive. For people like myself, it is an important number for manufacturing processes, and yea, for velocities. I guess when you get an intuitive feel for math, its like another data point worth noting.