question for the experts

IIRC, at 100 yards, 1 MOA= 1.034 inches

which, for most purposes, we simply round to 1"= 1MOA,

So, for a single hole, I measure the greatest width, subtract caliber and call that the MOA

so in your case, .42-.223 = .2 = .2 MOA

OR

I take a pic with my phone (with something measuring 1" in the image somewhere, and use this program:

http://ontargetshooting.com/

Which is far more accurate, and gives you a nifty record that looks like this:

100 yards = 3600 inches.

Tan(0°01')*3600 in = 1.047 inches (1 MOA @100 yards)

0.42 in = 3600 in*Tan(x)

0.42 in at 100 yards is 0°00'24" or 0.4 MOA

316SS said:

100 yards = 3600 inches.

Tan(0°01')*3600 in = 1.047 inches (1 MOA @100 yards)

0.42 in = 3600 in*Tan(x)

0.42 in at 100 yards is 0°00'24" or 0.4 MOA

Click to expand...

But his group size is more like .2 than .42 - got only account for the very center of each bullet hole otherwise the bigger the caliber the worse a single hole MOA accuracy would be. The first reply seems right to me...

Doc7 said:

But his group size is more like .2 than .42

Click to expand...

Whoops, right you are. That's what I get for scanning and not reading carefully.

Nice group.

BTW Ramone is right about On Target being a great program for figuring target group size. It calculates MOA as well as the actual size of groups. Of course the stuff can all be done with a caliper and a little math but that's why we all use computers - because we're too lazy to do it the hard way. We get the same results either way. Also the program has the common bullet hole sizes for popular caliber bullets but the best way is to measure an actual hole and use that as the size because sometimes the paper can give you a false reading. For example a really thin type of paper might get bent back around the edges of the hole giving a person a larger size for bullet holes than they should have especially if the bullets you're shooting happen to wobble some before they hit the target.

I have a caliper but I rarely use it. I use the software instead. You can zoom in on the holes and get really good measurements IMO. It's best to use a scanner if you can but a camera will work. It's always good to include something of known size so you know the camera or scanner are set to properly get the right size on things. So if your camera happens to be using a lens that is distorted or set to zoom in or something then you will know about it and you won't have problems.