The Firing Line Forums - View Single Post - I'm looking for a technical definition of MOA

Ruben Nasser · December 31, 2000, 07:22 AM

Destructo, your math is right, but a MOA group is defined, as Jim Keenan put it: "...a group of shots within a 1"... Conventionally, groups are five shot unless otherwise specified,and group size is measured center to center of the farthest apart bullet holes."
So, we are not dealing with the deviation of the shots from the theoretical path (which, as you said,would lead to a 1" radius, and thus 2" grouping), but what we are doing is measuring the angle that subtends (covers) the entire group.
Then by definition, this arc (it's an arc, but due to the minute angle we can aproximate it to a line for the calculation you just did) it's the diameter of the group.

December 31, 2000, 07:22 AM	#11
Ruben Nasser Senior Member Join Date: March 29, 2000 Location: Asuncion, Paraguay Posts: 280	IT'S A 1" DIAMETER!!!! Destructo, your math is right, but a MOA group is defined, as Jim Keenan put it: "...a group of shots within a 1"... Conventionally, groups are five shot unless otherwise specified,and group size is measured center to center of the farthest apart bullet holes." So, we are not dealing with the deviation of the shots from the theoretical path (which, as you said,would lead to a 1" radius, and thus 2" grouping), but what we are doing is measuring the angle that subtends (covers) the entire group. Then by definition, this arc (it's an arc, but due to the minute angle we can aproximate it to a line for the calculation you just did) it's the diameter of the group.