I know moa = minute of angle, but what do contributors mean when they are referring to moa related to accuracy / sighting in , etc.? Statements like: "go for the additional moa", etc.? How does moa relate to inches of shot group diameter? I think that's what I'm trying to ask here.

Thanks!

What makes MOA a useful unit to measure accuracy is that it is independent of distance. Imagine drawing two lines downrange from the end of the barrel that diverge from each other at a given angle. The farther you get downrange, the farther the lines will diverge.

Most believe that the best way to express the variance between shots in a group is by using this angle rather than using a group size, because group size is only meaningful for a given distance.

The bottom line is that one MOA results in a group that is 1" in diameter at 100 yards. At 200 yards, it would be 2 inches.

This also becomes important when zeroing in your scope as the adjustments on the turrets are in minutes. A one minute adjustment in the scope will move the point of impact 1" at 100 yards, 2" at 200 yards.

I'll go ahead and post this since it's all typed out, but evidently I forgot to hit the Submit button and Carl has already answered you, too.

Well, this may be a little more info than you wanted, but here it goes. A minute of angle is a measurement of an angle and is 1/60 of a degree. Think of two shots from a rifle being straight lines from the muzzle of the rifle to where the bullets impacted the target. The angle made between those lines is what people are talking about when they talk about their groups being a certain "moa" measurement. The specific angle they're talking about is the angle made between the lines from the gun's muzzle to the impact points of the two bullets that hit farthest apart.

Now with all that extra info that doesn't matter, here's the simple version. One minute of angle isn't exactly half an inch at 50yds, but it's very close. By the same token, one moa is almost exactly 1 inch at 100yds. Think of an angle on paper where the lines get farter apart the farther they get from place they insersect to form the angle. With that concept in mind, it's pretty easy to see that as distances get farther the distances between bullet impact points to make a certain "moa" group size increases (1moa is about 5" at 500yds, 10" at 1000yds, etc.).

When you're measuring group size, measure the distance between the centers of the two bullet holes farthest apart. The easiest way to do this is measure the outside edge to outside edge and then subtract the width of one bullet hole from that. For example, if you shot a 10-shot group with your 22lr at 50yds and the center-to-center distance between the two holes farthest apart was 0.98", then that's just under 2 moa since the distance was 50yds.

Here is a link to more than you may want to know....

http://members.cox.net/riflesilhouette/targets1.htm

Quoting a shooter who is much better that me "A good center hold and break will make up for a lot of bad judgement in silhouette shooting"

Kitty