outdoorslover,
Let me start by commending you on your insight. I noticed in your other post that you continued to shoot into the same target throughout the entire shooting session. Thats pretty cool and show you want a good picture of all the uncertainties involved in hitting your point of aim. I'll try to answer your questions as best I can.
what if you get a 2' group and then flinch one and see it out 6"
Before the flinched shot you have a 2" group,when you flinch you can miss by 6". The 2" group tells you that you can repeat your pointing skill very well, the flinch shot tells you how far you can miss if you happen to flinch. I have to admit, I appreciate the honesty of the 6" miss, this kind of miss is something you will over come because you recognize its source.
Also do you shoot a certain number of shots into a group
I like to do 4 or 5 shots to a group. Folks tend to shoot 3 shot groupings because they are easy to analyze, and I often do. The centers of the groups are easy to find for one thing (so when you are moving sights this is a bonus). The more shots you analyze though, the more it tells you about your POI uncertainties. So if its 3 shot groups, one wants to consider the attributes of a few of them as opposed to the best grouping of a few.
How would you measure a group?
Most folks measure the greatest spreadto calculate their group size, basically a circle which passes through the centers of the two most distant bullet prints. Another method is to calculate mean radius.The idea here is where should the POI be and how far off is the average miss. Both are useful method of analysis but if you post a particular group size without commenting on the method, most will assume the prior and not the latter.
Keep practicing and you'll continue to improve.
Added: Outdoorslover, here's how you find the center of a 3 shot grouping. I think the picture says it better than I can, but if it isn't clear, just ask.
