Cheap .22 ammo test

I did a test of 3 cheap .22 ammos today. Federal Lightning 510b, CCI Blazer, and CCI SV Blue Cardboard Box. When I measure the groups, where do I measure from? Outside of the widest 2 shots? Inside edge of the outermost holes? Center of the outermost holes?

I would like to give a report, but I want to give the report in a way that makes some sense.

How about outside to outside and subtract .11??

err... center to center.
If you want to measure outside to outside, you can subtract .22.
Any way you do it, just let us know how you measured it, when reporting the results.

Ok, measurements are done. I'll post it all later. Going to the range to practice.

when measuring groups take your digital calipers and measure 1 bullet hole from same ammo. measure the grease mark left by the bullet then zero the calipers at this measurement. now measure the group at its widest part and that will give you your c.t.c group size hope this helps