Well, I like to work up loads using velocity as a data point along with groups. I have found that a very accurate load at 100 yards might have a large std dev. in velocity. Then when you shoot 600 yards or more, now you have to worry about not only spread from the group, but now vertical stringing. So for a deviation of 50ft/sec. that can open your groups up 4 more inches at 600 yards. So it is a part of my load workup routine. Its not really the shade that hurts me but the lights under the shed. They put off that 60hz tone which as you know makes a chrono go nuts. Thanks, I went ahead and ordered the printer.