What MOA?

center to center.

1moa = 1/2" @ 50 Y/M
1moa = 1'' @ 100 m
1moa = 2" @ 200 m
1moa = 5" @ 500 m
1moa = 10" @ 1000 m
1moa = 20 @ 2000 m

Etc

Since it is very difficult to "eyeball" the center of your bullet holes, measure your groups outside to outside and then subtract one bullet diameter (.308") to give you your center to center measurement. All groups are measured center to center.

Dale

I just read your post again and looked at your picture. You need to find the two bullet holes farthest apart to measure them. Not necessairlly side by side, it may be at an angle or top-bottom. The four holes I see in your photo are larger than a 1/4" group. not sure where your fifth round is. Measure your holes from top right to bottom left and see what your group size is. (Your calipers appear to be off also. Your 1/4" is larger than your .308" bullet hole!)

Dale

The calipers are hard to read in this pic but it is actually a little over 5/16ths of an inch. I bought some digital calipers since and just took another pic of the targets

View attachment 13553
View attachment 13554

If that was at 50 then this is how you figure your group size in MOA.

You measure the two impacts that were farthest apart from outside edge to outside edge.
Subtract .308.
Calculate the MOA taking in to account that 1 MOA at 50 yards is 1/2".

So if that 0.95" reading is the outside to outside measurement then you subtract .308" and you get 0.642". Divide 0.642" by 0.5" and you get 1.284 MOA.

Thank you all for your input; I have a better understanding now; looks like I got some more practicing to do....

Thanks powder for asking this question. like teacher used to say.."if you have a question, ask. others may want to know as well!"

I found that measuring the outside edges of the bullet holes typically gives a "Better" result than using the points on a dial caliper and measing the apparent center to center of the extreme spread (furthest apart). I prefer to measure center to center because for me, it is much more consistent.

Try measuring by extreme spread and then adjusting your dial calipers to the number calculated and seeing if it comes close to being accurate if you look at the holes center to center. I believe the reason for this is because the bullet holes (and black outlines) are typically smaller than the nominal size of the bullet.

Works well enough for me. YMMV.
- Ivan.

To save some math why not just measure either to the leftmost side of the furthest holes or the rightmost side of the furthest holes...

Rick

OnTarget Software

Go here http://www.6mmbr.com/ontargetsoftware.html

This is an awesome computer program called OnTarget. It tells you EXACTLY the MOA of your group. All you gotta do is take a digital camera and snap a picture of your target. You will need some kind of reference for the computer measurements so I just hold up a penny flat against the target for this. The web article should walk you the whole process. It works for both Mac and PC.

I use this software and love it. It helps reduce group size evaluation errors. In some cases I save the displayed data as a photo and then include it in a pdf report on the load test.

JSimm87 said:

Go here http://www.6mmbr.com/ontargetsoftware.html

This is an awesome computer program called OnTarget. It tells you EXACTLY the MOA of your group. All you gotta do is take a digital camera and snap a picture of your target. You will need some kind of reference for the computer measurements so I just hold up a penny flat against the target for this. The web article should walk you the whole process. It works for both Mac and PC.

Click to expand...