If you just found a target with a group on it, if you are willing to make the following two assumptions, you could compute some data from it which might be helpful:
-All shots were fired at the same aiming point
-The aiming point is known (for instance the center of the bullseye might be a good guess [could be wrong though])
Once you do that, if you want to do things the manual way, you could make a grid system on the paper with X-Y coordinates. Measure the X and Y coordinates of each shot and the find the average of the respective X values and the respective Y values. That would find your group center in theory. Depending on how many shots you have fired there, that location will may be more or less certain. 20 shots would be more certain the 3 shots. The difference between the center of your group and the aim point (POI vs POA) is your accuracy.
You could also determine the extremes of the group size or also determine the average radial dispersion from the aiming point you calculated. That would give you an idea of the precision. But that number is relative. As was mentioned, a 10" group could be world record break or absolutely terrible depending on the distance and what it was shot with.
Or you may do all this just to figure out some guy was patterning his shotgun for deer season haha.
-All shots were fired at the same aiming point
-The aiming point is known (for instance the center of the bullseye might be a good guess [could be wrong though])
Once you do that, if you want to do things the manual way, you could make a grid system on the paper with X-Y coordinates. Measure the X and Y coordinates of each shot and the find the average of the respective X values and the respective Y values. That would find your group center in theory. Depending on how many shots you have fired there, that location will may be more or less certain. 20 shots would be more certain the 3 shots. The difference between the center of your group and the aim point (POI vs POA) is your accuracy.
You could also determine the extremes of the group size or also determine the average radial dispersion from the aiming point you calculated. That would give you an idea of the precision. But that number is relative. As was mentioned, a 10" group could be world record break or absolutely terrible depending on the distance and what it was shot with.
Or you may do all this just to figure out some guy was patterning his shotgun for deer season haha.
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