I tried some different loads out in my .308 yesterday. The first five were light on powder compared to what I normally shoot and the second five were a little hot. I really didn't see any change in groups between the two. Both were a little worse than I normally shoot and were about 1.23" at 100 yards. Next I tried five shots .015" longer than I normally shoot and then I tried 5 shots .015" longer than that, or .030" longer than my normal load. Powder charge was what I normally shoot which is in between the light and hot loads I tried to start with. The .030" longer bullet fired the same size group as the first two loads. The .015" longer was a different story. I had 4 shots in one whole. I saved the 5th round just to make sure I wrote the length down right!!! That then brought up some questions. I was really surprised to see the my group size change that dramatically with a .015" change in seating depth. So I'm wondering how many of you have seen that sort of change in group size from such a small change in seating depth? Second, I realize that just because I got one great group from four bullets doesn't mean a whole lot. That could have been just luck. So what are some different thoughts on how many shots should be fired when checking a load?