Looking at some past posts about chronos, I just ordered a Magnetospeed Sporter . Should be here tomorrow. Now I have to understand some readout's that will be on the data. Such as extreme spread and standard deviation. What do they mean , what relationship do the have with velocity, how to tell if the readings are good or bad, etc. Should I shoot a 10 shot group to get an average mv ? It seems the older I get, the harder it is to understand somethings.😁. Thanks for any help.