How do you measure MOA?

MYNomad

Heading South
Dec 12, 2007
4,178
4,796
Pacific Northwest / West Coast Mexico
Name
Rick
Boat
Yes
Its been a while since I have done any target shooting, and I have a couple of rifles that are (I believe) sub-MOA, but I don't think I ever knew (and couldn't quickly find) an answer to my question. I know that a minute of angle is just over 1" (1.047" rings a bell) at 100 yards, and that the conventional test is to shoot a three-shot group within that distance.

But, if all of each hole has to be inside of 1" (which is as I recall it), then the centers of the bullet are even more tightly spaced (for example, 30 caliber bullets that are entirely within 1" have centers within 0.70". If so, that is substantially better than MOA accuracy (it is .7 MOA accuracy). Or, conversely, if it is proper to measure from bullet center, then the outside diameter of the circle that contains the entirety of each bullet hole could be 1.30". That is a HUGE difference. But it sounds right to me -- MOA must mean three bullets entirely within a 1.30" circle (at least with 30 caliber bullets). IS that right?
 
Upvote 0

invictus

AVD
May 26, 2006
4,488
2,193
Orange County
Name
Jason
Boat
Tiara 2000 Cuddy
1 MOA equals 1” at 100 yards plus that little weirdness remainder you noted.

So 1 MOA of adjustment left, would move the point of impact 1” left at 100 yards, measured at center of impact. And the 30 cal math would look more like 1.15 (radius not diameter).

A “1 MOA” rifle is a factory pitch claiming a repeatable group of 1” or less at 100 yards. Likely at center of impact as you noted.

1/4 MOA, 1/4” at 100. 1 MOA at 200, 2”, 300 at 3” and so on.
 
  • Like
Reactions: CartridgeCalls
Upvote 0

MYNomad

Heading South
Dec 12, 2007
4,178
4,796
Pacific Northwest / West Coast Mexico
Name
Rick
Boat
Yes
So 1 MOA of adjustment left, would move the point of impact 1” left at 100 yards, measured at center of impact. And the 30 cal math would look more like 1.15 (radius not diameter).
Perhaps I am missing something (I am usually pretty good at math), but if two bullets hit on opposite sides of a 1" circle, their outter edges would each be 1/2" (to the circle) plus .15" (half of the bullet diameter) from the center, so they would be 1.3 inches apart at the outter edges (not 1.15).
 
Upvote 0

Cast Gold

hss AHHHH...hss AHHHH....
Jul 1, 2005
2,769
635
Tustin
Name
Kris
Boat
Mike's
Align the target so that the most spaced-apart impacts are positioned so that you can clearly see the same portion of the circle on both. For example, if you can see the 3:00 position on the 2 holes that are furthest apart, or the 6:00, or the 12:00, or the 9:00. You measure from those same tangential points on both holes, which would be equivalent to measuring center to center. You can also scan the target and import into MS Paint, draw circles that are centered over your impacts, print and measure with a caliper.
 
Upvote 0

invictus

AVD
May 26, 2006
4,488
2,193
Orange County
Name
Jason
Boat
Tiara 2000 Cuddy
Measure from center of holes and ignore bullet diameter.
MOA is the same for .223 as it is for .416 etc.

This was the idea I was trying to convey. Center of mass of the actual strike is the measuring point, typically.

Your talking about the total circumference of the group. That is typically not what is used.
 
Last edited:
Upvote 0

CartridgeCalls

100% Disabled Veteran Owned Small Business
Apr 29, 2015
5,478
871
Palmdale, CA
www.ebay.com
Name
Curtis Wright
Boat
Kayak
Most modern rifles are capable of submoa groups. Most shooters aren't.
 
Upvote 0

Johnlgarrison

I Post A Lot But I Can't Edit This
  • Jul 27, 2009
    2,672
    1,965
    63
    Temecula CA USA!
    www.inkspotsgreatdanes.com
    Name
    Johnny Garrison
    Boat
    Parker 2320 "Sticky Business 5"
    MATH!!!!!
    Are you freaking kidding me MATH!
    First they do away with Babe of the Day and now MATH. I’m outta here.

    just kidding

    my favorite rifle is my 1944 British Enfield. 303.
     
    Upvote 0

    Kman

    I Should Upgrade My Account
    Apr 7, 2003
    1,915
    2,696
    So Cal
    Name
    Kurt
    Boat
    Robalo R180 Trailer Trash
    We always did 5-shot groups on varmint rifles and measured center to center.
     
    • Like
    Reactions: CartridgeCalls
    Upvote 0

    CartridgeCalls

    100% Disabled Veteran Owned Small Business
    Apr 29, 2015
    5,478
    871
    Palmdale, CA
    www.ebay.com
    Name
    Curtis Wright
    Boat
    Kayak
    I know Nate and a few others have had bad experiences with late production Rem 700s, but my last three were all 1 MOA or less.

    Im not a fan of any of the newer Remingtons 700/710/783 myself. But I have shot a few deer and coyotes with them. Most of them are lucky to shoot a 2" group with factory ammo. Hand loads can be better.
     
    Upvote 0

    okie man

    I Post A Lot But I Can't Edit This
    Oct 24, 2006
    3,930
    767
    new palestine indiana
    Name
    kerry way
    Boat
    18' javalin
    upload_2019-10-24_20-15-5.jpeg
    This is sub moa
     
    • Like
    Reactions: BloodyL
    Upvote 0

    Wild Bill

    Not Blackmouthing
    Aug 4, 2010
    3,620
    3,810
    Camano Island
    Name
    Steve
    Boat
    Otter Craft
    426EBCA8-30F9-47FB-A0CD-E66C0C1A1170.jpeg
    This is definitely sub moa
     
    Upvote 0

    matt86m

    Not worthy of a Title
    Apr 6, 2010
    2,517
    743
    Fountain Valley, CA
    Name
    Matt
    Boat
    20' Tiara Pursuit
    Center hole to center hole of the 2 farthest in your group of 3 or 5 is the typical. No need to adjust for the caliber or size of the hole.

    1'' group at 100 yds
    2'' group is 200 yds
    3'' group at 300 yds
    Etc.
     
    Last edited:
    Upvote 0

    invictus

    AVD
    May 26, 2006
    4,488
    2,193
    Orange County
    Name
    Jason
    Boat
    Tiara 2000 Cuddy
    Im not a fan of any of the newer Remingtons 700/710/783 myself. But I have shot a few deer and coyotes with them. Most of them are lucky to shoot a 2" group with factory ammo. Hand loads can be better.

    The 710’s are garbage, 783’s not much better.

    Did have a 710 in 30-06 that was 1.5” gun, however, it had some headaches that were a PITA, magazine, bolt catch, it is clearly budget.
     
    Upvote 0

    Jim n Texas

    Member
    May 12, 2012
    692
    252
    TEXAS
    Name
    Jim
    Boat
    None
    I like it when you can’t measure center to center due to all shots are in one hole a little larger than caliber.[ATTAC]

    upload_2019-10-27_12-27-0.jpeg
     
    Upvote 0

    el Toro

    I Post A Lot But I Can't Edit This
    Feb 19, 2003
    9,157
    1,633
    Point Loma
    Name
    Nate
    Boat
    Artemis
    Nerd alert! Center to center or edge to edge and subtract bullet diameter. Same thing. 3 vs 5 shots is a personal thing. Most rifle “guarantees” based on moa are for 3 shots.
     
    Upvote 0