MOA readings

Discussion in 'Long Range Scopes and Other Optics' started by highcountryhunter, Apr 2, 2008.

  1. highcountryhunter

    highcountryhunter Member

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    All right, dumb question. Say your scope has 56 MOA of adjustment. What does that mean. Is that 56 inches up or down at a 100 yards if so, what about at 600 yards. Now when you turn the turrets to adjust for drop, do you have to figure the MOA at that distance or does it do it automatically when you do the math for the given yardage. Sorry for the elementry question, but I'm trying to figure out if a scope will have enough adjustment for the given distance......Thanks
     
  2. Ridge Runner

    Ridge Runner Well-Known Member

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    1 moa is 1.047" per 100 yards of range, so those 4 1/4 MOA clicks will move the bullet 1.047" at 100
    2.094" at 200 (1.047"x2=2.094)
    3.141" at 300 (1.047x3=3.141") and

    9.1089" at 870 yards (1.047"x8.7=9.1089")

    MOA= a unit of angular measurement equal to 1/60th of 1 degree which equals 1.0473" per 100 yards.
    there are 21,600 MOA in a circle, and 1 moa at the end of your 24" muzzle is .00698", hope this helps
    RR
     

  3. britz

    britz Well-Known Member

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    + 1 for ridgerunner.
    Most scopes are actually set up in inches per hundred- so you have to figure out which yours is. I know nikon, Busnell, Zeis (I think) and many others are set up in inches per hundred (4 clicks = 1 inch per hundred yards)
     
  4. highcountryhunter

    highcountryhunter Member

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    OK, it's obvious that I am new to this MOA thing. If a scope has the 56 MOA adjustments, and my bullet drops say 58" at 600 yards, is there enough adjustment to calculate for bullet drop. Again thanks for the replies.......
     
  5. britz

    britz Well-Known Member

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    Yes. most likely
    60 inches at 600 yards is 10 inches per hundred yards. Inches Per hundred Yards (IPHY) is very close to MOA (1.047" per 100). If your scope has 58 MOA adjustement, you will likely have about 29 MOA of elevation (half of the total MOA of adjustment). I can't say for sure because sometimes scopes are mounted in such a way that you use up more of the elevation adjusment to atain a zero because the scope is mounted at a slight angle. BUT, most of the time your scope and bore will be paralell to eachother allowing you approximately half of your total adjustment to be useful in elevation adjustment after you are zerod in at 100 yards (half of the ajustment would be available for raising your crosshair and half would be avialable for lowering your crosshair).

    When we say Inches Per Hundred Yards (IPHY), it is just that: so many inches of elevation for every hundred yards. So for the next few examples we will use the following number that I pulled out of my hat - 15 (IPHY). If you take 15 inches per hundred (what many incorectly call MOA), for every hundred yards you move away - you multiply the moa by that number inorder to atain the actual drop at a certain range. Ie. if you are at 100 yards you take 15 (IPHY) x 1 = 15 inches. if you are at 300 yards you take 15 (IPHY) x 3 = 45 inches. if you are at 800 yards you take 15 (IPHY) times 8 = 120 inches and so on.

    I decided to add this to help clairfy the difference; if you take the same case in MOA, it would be 15 moa is (15 x 1.047 x how many hundred yards). Ie. at 100 yards you take 15 x 1.047 x 1 = 15.7". 15 MOA at 300 yards is 15 x 1.047 x 3 = 47.1". 15 MOA at 800 is 15 x 1.047 x 8 = 125.6".

    here is where it gets tricky 1 MOA is acutally 1.047 inches per hundred yards. This means vertually nothing at close and mid range. However, when you start to adjust your scope 15-20 units (MOA or IPHY)and are trying to hit a target at several hundred yards away. that .047" per unit per hundred yards starts to add up in a hurry. My 300 wsm with a zero at 200 will miss a 600 yard target by something like a foot ( slight exageration I guess) if I am using calcuations for MOA and adjusting a scope that is set for IPHY.
     
    Last edited: Apr 3, 2008
  6. Moman

    Moman Well-Known Member

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    I'm pretty new to the MOA concept as well but what is helping me is to just consider MOA as 1" @ 100 yds. I am using this initially just to help me understand the concept. Yes I understand that 1.047 is technically correct, but that will come in time.

    When you adjust your scope 1 MOA, that moves your point of impact 1" @ 100 yds. That same 1 MOA adjustment moves your POI 2" @ 200 yds, 6" @ 600 yds, etc. So the way I understand it is moving your scope 56 MOA would be 56" @ 100 yds.

    If you needed to adjust for a bullet drop of 2" @ 100 yds, that would be 2 MOA. If you needed to adjust for a bullet drop of 2" @ 200 yds, that would only be a 1 MOA adjustment.

    I hope this helps to get you started. Maybe someone like Shawn will chime in and give us all a quick lesson.
     
  7. Willys46

    Willys46 Well-Known Member

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    Easy but not Precise

    I use the 1 inch - 1 MOA @ 100yrd.
    How i do it. Run your drop chart like you did 58" come ups for 600yrds. Divide 58 by 6 = 9.66 MOA. I would round it to the nearest .25 moa assuming your scope it 4 clicks per 1 MOA. I would try 9.5 MOA or 9.75.

    Just drop the zeros and divied you inches by that number. for 550 yards divide by 5.5

    Willys
     
  8. Ridge Runner

    Ridge Runner Well-Known Member

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    ok you have 56 MOA of elevation, range is 600 yards, trajectory is -58" so, lets do this
    58" / 1.047 (moa)/6 (range in hundreds of yards) = MOA elevation needed
    58"/1.047= 55.4 (rounded up slightly) 55.4/6=9.23

    So it would take 9.25 MOA (37 1/4 moa clicks) to make zero at 600 if your -58" low, each click would move your point of impact 1.57" (1.047/4= .26175x6=1.5705") at 600 yards (1.57x37= 58.09"), so yes 56 MOA of elevation is plenty to make a 600 yard zero.
    RR

    Remember you not just raising the bullet, your changing the bullets angle of departure so the POI is going to move more as the range increases. so those 56 MOA of adjustment will change the POI 351" at 600 yards if you turn the scope all the way up.
     
    Last edited: Apr 4, 2008
  9. highcountryhunter

    highcountryhunter Member

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    All right, my ignorance is coming through again. Thanks for all the replies, it answered a lot of questions however now I have one more. After doing the math I need to adjust for 9 moa. Now that equals say 37 "clicks", what does the 0-14 mean on my target turrets. Is there a book or website I can go to so I stop waisting your guy's time.......
     
  10. ss7mm

    ss7mm Writers Guild

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    You've never said what scope you have or are using for reference but some scopes have 10 moa (or ") per revolution of the turret and some have 15 per revolution. You can't show the zero as well as the 15 so it reads from 0-14, 15 would be one full turn stopping on the zero. If you scope is designed using moa then each full number on the turret would be 1 moa increment. You should have 4 small marks between each full number. They are 1/4 moa adjustments.

    There is a good website where you can get information. And......you are there.;);)
     
  11. mattj

    mattj Well-Known Member

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    Usually it's one number per MOA --- if you know what your click values are, you should be able to verify this on the scope.

    For example, if you know your scope has 1/4 MOA clicks, then it should take 4 clicks to go from the hash marked '0' to the hash marked '1' on your turret.

    Note that the 0-14 markings are only correct on the first turret rotation -- so if you had to do 16 MOA, then you'd have to do a complete rotation of the turret, and then 8 more clicks (so you would end up on the hash marked '2', but you'd be adjusted for 16 MOA of elevation). Just make sure you don't lost track of what rotation your turret is on.

    Edit: Oh yeah, what Dick said -- back around to zero again would probably be 15 MOA, so if you dialed around to 16 MOA, you'd probably end up on '1'. But yeah, depends on your scope.
     
  12. CAM

    CAM Well-Known Member

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    ss7mm
    There should only be three smaller marks! 1/4, 1/2, 3/4
    Just to clarify, carry on!

    This comes up so often we need a sticky or a tech article.
    I think the hardest thing for newby's is that MOA is an angular term.
    They want to give it a mesurement/size that they can relate to when in fact it "is" the mesurement, "Minute-Of-Angle"

    MOA= 1.047 inches only at exactly 100 yards!!
    MOA= 10.47 inches only at exactly 1000 yards.
    MOA= .01047 inches at three feet or one yard!
    It is a very small angle it is 1/60 of one deg.

    CAM
     
  13. ss7mm

    ss7mm Writers Guild

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    :eek:Good catch. My brain knew what I was thinking but my fingers get a little carried away some times.:rolleyes:
     
  14. highcountryhunter

    highcountryhunter Member

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    I just got a Leupold VX-III 6.5x20 L/R Target. Its going on a Rem. 700 that was just converted to a 300 Dakota. The scope has the large target knobs that read from 0 to 14. You are right, if you were to count, going back around to zero that is actually 15. Now with everyone talking about clicks and adjustments, if I needed to go to 9moa to adjust for drop at the given yardage do I need to count the 37 clicks or just turn the knob until I get to 9. It should be just the same yes no. This is whats confusing me.