I do the same thing bigcountry does only I shoot 3 each 5 shot groups at 100 then 200 yds. I set up targets for each load and each group for that load and mark each group/target with the load info and range. This takes a good deal of time especially at the 200 yd targets but it give the barrel a chance to cool down.
Also, to allow for consistancy, I start with a clean barrel and clean between each group. Some may say that's crazy but that's my method. I figure if I'm going to be hunting with a clean barrel I want to know where my first shot is going to go, especially if I have to shoot at 300+ yds.