#1: confused Author: HayCreek, Location: Central NDPosted: Tue Sep 13, 2011 9:22 am ---- When I plot some data for my round, zeroed at 200 yds., the trajectory shows a drop of 6 inches at 300 yds. When I check the MOA table it tells me to correct for a 300 yd shot I should come up 2.1 MOA. That's only 2.2". Am I missing something?
Thanks for any help.
#2: Re: confused Author: Dawgdad, Location: On the PrairiePosted: Tue Sep 13, 2011 10:23 am ---- About a quarter of an inch... maybe a bullets width.
Most likely a rounding issue.
#3: Re: confused Author: Dawgdad, Location: On the PrairiePosted: Tue Sep 13, 2011 10:28 am ---- Actually .. the drop would be 6.6 or 6.9 for those MOA at 300...
Dallan?
#4: Re: confused Author: Pumpkinslinger, Location: NC foothillsPosted: Tue Sep 13, 2011 2:11 pm ---- Isn't 2 MOA equal to about 6" at 300 yards?
#5: Re: confused Author: Ominivision1, Location: IowaPosted: Tue Sep 13, 2011 2:22 pm ---- You should understand that an English inch and a Minute of Angle (MOA) is not the same thing. They are units of measurement that happen to be extremely close in value. However, they are close enough together that for the rest of this explanation please simply round down to an inch.
Exact Minute of Angle (MOA):
1 MOA = 1.0471996 inches @ 100 yards.
1 MOA = 5.24 inches @ 500 yards.
1 MOA = 10.47 inches @ 1000 yards.
Rounding MOA
1 MOA @ 100 yards = 1 inch
1 MOA @ 200 Yards = 2 inch
1 MOA @ 300 yards = 3 inch
1 MOA @ 400 Yards = 4 inch
1 MOA @ 500 yards = 5 inch
1 MOA @ 600 Yards = 6 inch
1 MOA @ 700 yards = 7 inch
1 MOA @ 800 Yards = 8 inch
1 MOA @ 900 Yards = 9 inch
1 MOA @ 1000 Yards = 10 inch
Minute of Angle as it applies to group size and drop
MOA is used to measure group sizes. A 1 inch group @ 100 yards is referred to as a 1 MOA group. A 2 inch group @ 100 yards is a 2 MOA group.
At 100 yards it seems simple enough to understand. However, it can get confusing if you’re not used to the terminology when you move beyond 100 yards. For example: a 3 inch group shot at 300 yards is also a 1 MOA group. A 6 inch group shot at 300 yards is a 2 MOA group. A 1 ½ inch group shot at 300 yards is a .5 MOA group.
Another way to look at it is like this:
½ MOA @ 700 yards is 3.5 inches
1 MOA @ 700 yards is 7 inches
2 MOA @ 700 yards is 14 inches
3 MOA @ 700 yards is 21 inches
3.5 inches @ 700 yards is ½ MOA
7 inches @ 700 yards is 1 MOA
14 inches @ 700 yards is 2 MOA
21 inches @ 700 yards is 3 MOA
Calculations:
How many inches equal 4 MOA at 700 yards?
* (MOA x yards) / 100 = inches
(4 MOA x 700 yards) / 100 = 28 in
How many MOA equal 21 inches at 700 yards?
*(inches / yards)100 = MOA
(21 inches / 700 yards) 100 = 3 MOA
5 inches = 1 MOA how many yards away is the target?
(Inches x MOA)100 = Yards
(5 inches x 1 MOA) 100 = 500 yards
*You can drop the last step and make the calculations easier by moving the decimal on the yards two places to the left.
How many inches equal 4 MOA at 700 yards?
(4 MOA x 7.00 yards) = 28 in
How many MOA equal 21 inches at 700 yards?
(21 inches / 7.00 yards) = 3 MOA
Minutes of Angle and Rifle Scopes
Most hunting and target scopes adjust in Minutes of Angle (MOA). The most common adjustment is ¼ or .25 MOA per click. Although not as common, there are scopes that adjust in 1/8, 1/6/, 1/5, 1/3, ½, and 1 MOA .
¼ MOA at 100 yards literally means that each time the scope turret is clicked the bullet impact will move ¼ or .25 inches.
To move the bullet impact 1 inch you would need 4 clicks (.25 x 4 = 1) Example: When sighting in a rifle the bullet needs to move up 5 inches to hit the center of target. 5 in / .25 in = 20 clicks or you could think of it like this: need to move 5 inches, 4 clicks per inch, 5in x 4 clicks per in = 20 clicks.
Another application for understanding MOA and scope or sight adjustment is when shooting longer distances. Rifle is sighted in at 100 yards. Your ballistic program tells you that you need to come up 20 MOA to shoot at 600 yards. 20 MOA / .25 = 80 clicks Or 20 MOA x 4 clicks per MOA = 80 Clicks