close
Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Chatting and General Stuff > General Discussion

General Discussion Must wear red or OD green socks to participate. I can't see your socks, please be honest.

Reply

MOA/ Click type question

LinkBack Thread Tools Display Modes
  #1  
Unread 06-10-2009, 09:30 AM
Platinum Member
 
Join Date: Feb 2008
Location: Wampum, PA
Posts: 1,530
MOA/ Click type question

For some reason my brain isn't cooperating with me today. I went out this morning to do a trajectory validation and check my spin drift but it was so foggy I couldn't see past 100 yds. So I decided to try to find out the actual click value of my scope. Didn't want to waste the trip and had to go to work.

Here is the info:

Distance to target 107 yards
advertised click value of scope 1/4 MOA per click

I shot a 3 shot group at my zero dot then I dailed 28 MOA up and shot 3 more.

From center to center (top group to bottom group) I have 30 9/16"

What the heck is my actual click value?
__________________
"I may be dumb, but I'm not stupid." - Terry Bradshaw
Reply With Quote
  •   #2  
    Unread 06-10-2009, 10:54 AM
    Silver Member
     
    Join Date: Nov 2008
    Location: Federal Way, WA
    Posts: 204
    Re: MOA/ Click type question

    I'll take a crack at it.

    At 107 yards, 1 MOA=1.07"

    you have 30 9/16" or 30.5625"

    (Sorry, I'm an engineer by trade and prefer to work in decimals)

    30.5625"/1.07"=28.5631 MOA

    If you dialed up 28 MOA that means you went up 112 clicks on your scope (28 MOA X 4 clicks per MOA)

    If you actually got 28.5631 MOA that means that each click was worth .255 MOA

    By this reasoning The actual MOA/click value is .005 MOA greater than advertised.

    If this is correct than at 1000 yards each click would give an additional .05" of elevation above the 2.5" that 1/4 MOA would be.

    This is also assuming that MOA means 1" at 100 yards. I know there's some other definitions out there but that's another issue.

    I hope someone double checks me on this.
    Reply With Quote

      #3  
    Unread 06-10-2009, 11:32 AM
    Platinum Member
     
    Join Date: Oct 2005
    Location: Michigan
    Posts: 2,232
    Re: MOA/ Click type question

    406Pat, pretty close.

    You needed to use 1.047" for MOA at 100yds, which gives 1.12029"/moa at 107yds

    28moa*1.12029=31.37

    Spread of group is 30.5625" for a difference of .81" or .72moa difference.

    If the gun and shooter were perfect, then the scope would be off by .72MOA, however I don't know how large the groups are. Unless the gun and shooter are both worldclass (less than 1/4moa group sizes), then I would trust the scope.

    AJ

    ps: Hopefully, someone will double check my calcs.
    __________________
    If some is good and more is better, then too much is just right.


    My mind is a raging torrent, flooded with rivulets of thought, cascading into a waterfall of creative alternatives
    Reply With Quote
      #4  
    Unread 06-10-2009, 11:39 AM
    Silver Member
     
    Join Date: Jan 2008
    Location: Elko, NV
    Posts: 461
    Re: MOA/ Click type question

    Quote:
    Originally Posted by 406pat View Post

    This is also assuming that MOA means 1" at 100 yards. I know there's some other definitions out there but that's another issue.
    1" at 100 yards is referred to as "Shooters MOA".

    True MOA (Minute of Angle) is 1.047" (rounded) at 100 yards. To get this number take the tangent of 1 min (or .0166666 degrees) and multiply that by the distance in inches.

    At 107 yards a true MOA is 1.121" (rounded) at 100 yards

    Some scopes dial Shooter's MOA others true MOA.

    It looks like yours is Shooters MOA. The .005 difference per click in advertised value that 406Pat got using a Shooter's MOA is very close. The difference is most likely due to group variance and measuring error.

    Shoot more groups, re-calc, and see what you get next time.


    Paul
    Reply With Quote
      #5  
    Unread 06-10-2009, 01:07 PM
    Platinum Member
     
    Join Date: Feb 2008
    Location: Wampum, PA
    Posts: 1,530
    Re: MOA/ Click type question

    Quote:
    Originally Posted by AJ Peacock View Post

    If the gun and shooter were perfect, then the scope would be off by .72MOA, however I don't know how large the groups are. Unless the gun and shooter are both worldclass (less than 1/4moa group sizes), then I would trust the scope.

    AJ

    Defiantly not the case. However If I understand what your saying. Then there's not enough error for me to worry about, right? The bottom group was .75MOA and the top one was .2 (probably the best group I ever shot oddly enough). The gun is a 270 win.

    So what does being off .72MOA make my click value, .18846? (.72x1.047=.75384/4=.18846)

    What ever I get here for error is likely me. Just curious what you guys come up with.
    __________________
    "I may be dumb, but I'm not stupid." - Terry Bradshaw
    Reply With Quote
      #6  
    Unread 06-10-2009, 01:14 PM
    Platinum Member
     
    Join Date: Oct 2005
    Location: Michigan
    Posts: 2,232
    Re: MOA/ Click type question

    Quote:
    Originally Posted by jmason View Post
    Defiantly not the case. However If I understand what your saying. Then there's not enough error for me to worry about, right? The bottom group was .75MOA and the top one was .2 (probably the best group I ever shot oddly enough). The gun is a 270 win.

    So what does being off .72MOA make my click value, .18846? (.72x1.047=.75384/4=.18846)

    It would be (error)/(adjustment) or .72/28 or 2.571% error. Assuming you had shot it perfectly, that would make each click 1.047/4*1.02571=.2685moa.

    However, with only a single test, it is likely that your group center isn't actually the center of a larger sample size. If the center of the second group was actually at the top of the group, then your error would be reduced by .75/2 = .375, leaving an error of .72-.375 = .355. If the smaller group center was at the edge, that could reduce your error another .1moa.

    I would personally trust the scope, unless you can duplicate the measurement several more times. My guess is that your scope is very close (close enough to ignore).

    AJ
    __________________
    If some is good and more is better, then too much is just right.


    My mind is a raging torrent, flooded with rivulets of thought, cascading into a waterfall of creative alternatives

    Last edited by AJ Peacock; 06-10-2009 at 01:18 PM.
    Reply With Quote
      #7  
    Unread 06-10-2009, 01:22 PM
    Platinum Member
     
    Join Date: Feb 2008
    Location: Wampum, PA
    Posts: 1,530
    Re: MOA/ Click type question

    Thanks AJ. Thats what I was lookin' to hear.
    __________________
    "I may be dumb, but I'm not stupid." - Terry Bradshaw
    Reply With Quote
    Reply

    Bookmarks

    Thread Tools
    Display Modes


    Similar Threads for: MOA/ Click type question
    Thread Thread Starter Forum Replies Last Post
    Harris type S Bi-pod swivel type Iron Worker Other Stuff For Sale 1 05-24-2011 09:00 AM
    Redding Type-S die question cornstalker Reloading 4 04-08-2011 07:04 PM
    Leupold finger click dials - question bookworm Long Range Scopes and Other Optics 1 11-17-2009 02:12 PM
    Redding S type die question winmagman Reloading 3 04-26-2006 07:16 PM
    1/4 vs 1/8 click jameslovesjammie Long Range Scopes and Other Optics 9 02-16-2006 12:24 PM


    All times are GMT -5. The time now is 04:00 PM.


    Powered by vBulletin ©2000 - 2017, Jelsoft Enterprises Ltd.
    Content Management Powered by vBadvanced CMPS
    All content ©2010-2015 Long Range Hunting, LLC