First of thanks for this thread. I used to shoot with friends at least a couple a times a month and it all went away when Jon aka "Octopus" passed away. He was trying to teach me how to tune my rifle. He had a copy of a paragraph or two reprinted from this site I think. It was a bunch of rules the author used when tuning his rifle. He had decided that at his node every 1/10th grain of powder equated to so many fps and when the temperature changes so many degrees, the powder charge had to be changed a 1/10th to keep in tune. This "method " of tuning was pioneered by a well known shooter that had many wins to his credit. I had all intentions of copying these instructions but we went to the range and it never happened. But this method tuned by changing powder charge. The idea that I can make very precise preloads when I am at home and not being rushed makes much more sense to me. My rifle was bought from the classifieds here and one of the guys that shoot with us developed a load for me before I touched the rifle. And when the weather matches my load it shoots very good, but I cant get the weather to be right on command. They said I didn't know enough to shoot VV133 it would drive me crazy so the load is with H322. Ive thought that, that would be my load and I would preload if a barrel tuner was capable of making all the tuning changes necessary to stay in tune no matter what the weather was or how much it changed. If this is indeed possible, what tuner do you use and does it come with the chart that MKS talked about in his post. Cause that chart has to be worth more than gold.