In order to participate in the GunBroker Member forums, you must be logged in with your GunBroker.com account. Click the sign-in button at the top right of the forums page to get connected.
Options

Why am I getting 1 MOA = .524" at 100 yds?

BlckhrnBlckhrn Member Posts: 5,136
edited December 2005 in Ask the Experts
When I know it is just over an inch?

Pi x 100 (yds) x 36 ("/yd)
__________________________
360 (deg) x 60 (min/deg)
· Share on FacebookShare on Twitter

Comments

  • Options
    acdoddacdodd Member Posts: 1,314 ✭✭✭✭✭
    edited November -1
    Googled it.
    [url][/url]http://riflestocks.tripod.com/moa.html
    · Share on FacebookShare on Twitter
  • Options
    bobskibobski Member Posts: 17,868 ✭✭✭
    edited November -1
    the rounding rule?
    Retired Naval Aviation
    Former Member U.S. Navy Shooting Team
    Former NSSA All American
    Navy Distinguished Pistol Shot
    MO, CT, VA.
    · Share on FacebookShare on Twitter
  • Options
    BlckhrnBlckhrn Member Posts: 5,136
    edited November -1
    Thanks, still my math was off somehow. I was figuring 1 MOA at 50 yards with that formula, needed a circle of 200 yds to figure at 100 yards from center. Thanks for the link, his formula was the same as mine.
    · Share on FacebookShare on Twitter
  • Options
    armalite13armalite13 Member Posts: 7 ✭✭
    edited November -1
    would the deg. be 180 because you are talking about in front of you not behind you. http://www.shootingusa.com/SIGHTING_IN_SHOWS/25-07_MOA/25-07_moa.html
    · Share on FacebookShare on Twitter
  • Options
    CawdorCawdor Member Posts: 55 ✭✭
    edited November -1
    For 100 yards.

    The formula for the circumference of the circle is 2 X Radius X Pi.

    The radius = 100 yards.

    2 X 100 yards X 3.14159 (Pi) = 628.318 yards

    1 degree = circumference divided by 360

    628.318/360 = 1.7453 yards

    1 minute = 1 degree divided by 60

    1.7453 yards/60 = 0.0291 yards

    1 yard = 36 inches

    1 minute at 100 yards = .0291 X 36 = 1.0472 inches
    · Share on FacebookShare on Twitter
  • Options
    CawdorCawdor Member Posts: 55 ✭✭
    edited November -1
    Deleted - Double Post
    · Share on FacebookShare on Twitter
  • Options
    PelicanPelican Member Posts: 1,061 ✭✭✭✭
    edited November -1
    My wife says it's cause us guys always think everything is bigger than it really is. Hum, wonder what she means, didn't know she understood minute of angle.
    · Share on FacebookShare on Twitter
  • Options
    sandwarriorsandwarrior Member Posts: 5,453 ✭✭✭
    edited November -1
    The formula I use for figuring MOA is:

    MOA= 1/60th of one degree. Therefore 1/60 = .016667 If you convert that distance out to the distance you shoot you must convert this to a planer triangle. So you must find the Sine for it. If you have a scientific calculator take the sin of .0166667. (If you look at the calculator on your computer go up to view, hit the drop down and select scientific.)

    It is .00029 This is a constant no matter how far you shoot.

    If you want to measure MOA at the distance you shoot in inches find the number of inches at a given distance. i.e. 100 yds = 3600 inches. So...

    .00029 x 3600 = 1.047" @100 yds.= 1 MOA
    · Share on FacebookShare on Twitter
  • Options
    Ray BRay B Member Posts: 11,822
    edited November -1
    I'm not sure why you're using that formula, but it looks to me like you end up with the radius rather than the diameter, so yhou're off by a factor of 2.
    · Share on FacebookShare on Twitter
  • Options
    BlckhrnBlckhrn Member Posts: 5,136
    edited November -1
    Using that formula and those numbers to check the taper of a scope mount with .040 taper over 4 or 5 inches. I knew what 1 MOA was at 100 yards so was checking my math and, yes, as post above states was using 100 yards dia instead of 200.
    · Share on FacebookShare on Twitter
Sign In or Register to comment.