A while back I remember seeing an image that you could post at 25m which would help you figure out the size of your front sight post in MOA. This image had a 'v' shape that aided in this. Does anyone have a link or know where I can find it? Any help would be greatly appreciated! :~
As an alternative, take a squares target, on the upper left black out the column on the right of the square, 5moa
Upper right black out the columns on the right and left of the square. 6moa
Lower right, black out Left column and two right columns.7 moa
Lower left black out 2 left & 2 right columns.8 moa
Now photo copy and pass out as needed (stolen from JoeZ).
2 clicks low has a great point. Also, here are a couple of targets that have been out on the Appleseed forum in the past couple years.
My $0.02. What's wrong with measuring your sight with a caliper? A the "MOA" width will be the same at all distances; it will just subtend a larger space at longer ranges.
aj
Quote from: airplanejoe on August 11, 2016, 11:15:34 AM
My $0.02. What's wrong with measuring your sight with a caliper? A the "MOA" width will be the same at all distances; it will just subtend a larger space at longer ranges.
aj
I for 1 would need help with the math. If the front sight measures .12 and is located 24 inches from the rear sight what formula would I need? (it's been over 40 years since HS geometry).
2cl
For MOA it would be ArcTan(0.12/24)x60 = 17.2MOA I believe....
or approximate based on the assumption of 1MOA=1" @ 100 yards
0.12X100X36/24 = 18MOA
Quote from: NightFisher on August 11, 2016, 04:26:13 PM
For MOA it would be ArcTan(0.12/24)x60 = 17.2MOA I believe....
or approximate based on the assumption of 1MOA=1" @ 100 yards
0.12X100X36/24 = 18MOA
Thanks. I will add the formula to my calculator.
.120 sounds a little fat - I don't know it just sounds like it. My M14 has a font post of~ .080" width. The sight radius would typically be the distance from the shooter' eye in terms of calculating the angular width.
1 MOA at 25yds is about 1/4", so 18MOA at 25 yds would be about 4- 1/2" or so.
The tools that Thadeus posted look like they would work pretty well!
Be sure to post what you found out.
Sluggo, lets check my math with your M14. If you have a standard M14 your sight radius should be 26.75". That is rear sight to front sight, not eye to front sight. I was going to say you were wrong about the eye to front sight business but after I thought about it a bit I believe you are right when talking about angular width of the front sight so lets estimate your hold at 30".
Using those numbers I get your sight as ArcTan(.08/30) x 60 = 9.2MOA... Am I even close?
I have seen m1s and m14s that range from 7 to 9 or so MOA for the sight. Personally, I just use the tool and have since all we had were copies of a handmade version. 8 years of use this month tells me that the tool works. The math is not hard either and understanding it is good for those times that you lack other ways to tell.
Here are some other ways. An exterior door is 36 inches across. If you know the distance to the door and the width of the door, you can determine the width in MOA of the sight. The farther away you are the better. In other words you can reverse what we teach for ranging to measure the sight instead of the distance. You could also do this on the 100 yard range or 25m range with a series if targets of known sizes as described in the post above.
But no matter how you do it, learn your sight width or reticle widths for ranging. Don't get stuck in the weeds worrying about the difference between .2 and .3 MOA unless you have a system capable of being effected by those differences.
Ranging is helpful in many field situations. Also get out and shoot some KD. When you get used to seeing and shooting targets at actual distances, it greatly helps your ranging skills.
That brings us back to competitive marksmanship. Take that M1 or M14 or AR and go shoot a local match. Preferably at 200 yards or further, but 100 can do. Within 200 miles of my house there have been 4 Appleseed KDs this year. But within the same distance there have been more than 20 high power matches extending out to 600 yards, at least 6 3x600 matches (3 20 shot matches from prone all at 600). 5 1000 yards prone matches.
Within 20 miles of the house there have been 10 300 yard military silhouette matches m1s, 03s, various vintage iron sight rifles, no coats, no slings at an E type silhouette, there have been 6 high power silhouette matches 200, 300,385, and 500 m offhand with scoped rifle, no shooting coats, no sling. But you must use 6mm or larger. You get the idea. There are opportunities out there if you look for them that will help you to become a better shooter.
Not to get too technical from the folks involved in the SB Manual
Site width is W (in Sluggo's case 0.080")
Distance from eye to sight is R (in Sluggo's case 30")
A circle has 360 degrees, and there are 60 minutes per degree, so a circle has 21,600 minutes (or minutes of angle)
To find the MOA of your sight:
21,600 * (W / (2 * 3.14159 * R))
The circumference of a circle with your eye at the center and the sight at the edge:
(2 * 3.14159 * 30") = 6.28318 * 30 = 188.4954
How much of it the sight covers:
(W/188.4954) = 0.080/188.4954 = 0.00004244135400651687
Multiply that times the minutes in a circle:
0.00004244135400651687 * 21,600 = 9.1673 minutes.
In Sluggo's case (30"), your front sight would cover about 9.2 MOA.
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Site width is W (in 2 clicks low's case 0.12")
Distance from eye to sight is R (in 2 clicks low's case 24")
A circle has 360 degrees, and there are 60 minutes per degree, so a circle has 21,600 minutes
To find the MOA of your sight:
21,600 * (W / (2 * 3.14159 * R))
The circumference of a circle with your eye at the center and the sight at the edge:
(2 * 3.14159 * 24) = 6.28318 * 24 = 150.79632
How much of it the sight covers:
(W/150.79632) = 0.12/150.79632 = .00007957753876221913
Multiply that times the minutes in a circle:
0.0005863608 * 21,600 = 17.188 minutes.
In in 2 clicks low's case (24"), your front sight would cover about 17.2 MOA.
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All thanks to :bow: DonD who really is the master of this stuff, and me his lowly student.
Confirms my basic math belief:
NEVER DO MATH WITHOUT A MAINFRAME! #)
Now that I've seen the formula, I can program it.
2cl
Quote from: NightFisher on August 12, 2016, 10:44:54 AM
Sluggo, lets check my math with your M14. If you have a standard M14 your sight radius should be 26.75". That is rear sight to front sight, not eye to front sight. I was going to say you were wrong about the eye to front sight business but after I thought about it a bit I believe you are right when talking about angular width of the front sight so lets estimate your hold at 30".
Using those numbers I get your sight as ArcTan(.08/30) x 60 = 9.2MOA... Am I even close?
Sounds pretty close to me.( and mostly agrees with the post above)
Quote from: 2 clicks low on August 12, 2016, 12:49:09 PM
Confirms my basic math belief:
NEVER DO MATH WITHOUT A MAINFRAME! #)
Now that I've seen the formula, I can program it.
2cl
I am so anal about it that I use Excell and a caliper to adjust the front sight on my M1A. %)
I don't have it now but I had made up a panel on a sheet of cardboard, about 10" high and 6' long, with black inserts set apart that were the 10" height of the panel. The first was 4" wide, space, 5", space, 6" out to a 9" wide black insert.
Posted it at 100 yards under the target frame for Sunday KD and everyone on the line could aim in on the panel and determine the width of their front sight, or the distance of their crosshail/reticle. Cheap and easy.