If your target's lines are really 1" square, you would be close. We see you are attempting to measure outside edge to outside edge and subtracting .308. However your yellow line doesn't really go to the edges. AND, bullet holes are almost always smaller than nominal bullet diameter. You should measure from the true outer edge of the hole and then subtract TRUE bullet hole diameter as it appears on that paper. Otherwise, measure center to center.
Better Solution?
Use On Target software.
Get it HERE: https://ontargetshooting.com/
Just place the circles around each shot. Then the program will automatically calculate group size, measurement in MOA or mils, and distance to aimpoint.
I have tested On Target results against actual certified measurements, and it is normally accurate within about three hundredths of an inch (.03"). That is still more accurate than most measurements, particularly on the internet, where guys typically fib by a tenth or more.
That's why it is always best to put at least ONE round out of the group so's you can measure a single, clean hole.Set caliper to bullet diameter, then zero caliper. Now open caliper to outside to outside edges. Bullet diameter is already removed.
Best way to set caliper is on a bullet.
Editor: This is fast. That's good. But in most paper, the bullet hole is actually smaller than the bullet diameter. So above method will normally UNDER estimate the true group size.
I have no problem with that....lolThat's why it is always best to put at least ONE round out of the group so's you can measure a single, clean hole.![]()
That's why it is always best to put at least ONE round out of the group so's you can measure a single, clean hole.![]()
Gotcha,first I have to get them all in the same hole....lolUm, Muleman. You’re supposed to measure a bullet hole in the sighter for reference and the group should all be in one hole.

Yep that works for me.That's why it is always best to put at least ONE round out of the group so's you can measure a single, clean hole.![]()
No, bullet holes are all most always Smaller than actual size of bullet,you want to measure centers,center to center to get actual group sizeSet the printed lines to = 1"
Measuring tool says 0.69"
0.69"-0.308" = 0.382"
0.382"/1.047 = 0.365 MOA (at 100 yds)
View attachment 1101310 View attachment 1101311
Correct?
