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Mils and Moa Explained |
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Bags
Optics GrassHopper Joined: April/26/2007 Status: Offline Points: 24 |
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Posted: January/15/2008 at 08:55 |
There's a lot of confusion on "mils" and "moa". What really is a "mil". Is it based on 6283.2 mils (Marine) in a circle or 6400 mils (Army)? Same thing with moa vs "shooters" moa. Are the distance equations all the same?
Because I couldn't find a one source document on all these, I wrote a paper that discusses mathematically all these things and more. It is a revision of one that I did last year but this time I incorporated the Army mil (6400) and "shooters" moa. Plus I derived all the distance equations. I also cleaned it up a bit. Plus last page has a Quick Reference Chart. It's meant to be a one source document for any questions you might have and the whole thing doesn't have to be read front to back. I'm not good at making web pages, so the best I could do is the link below (the web site doesn't accept hot links), so you have to cut and paste. Any suggestions on how I could post this on-line at a better place would be appreciated. Bags Link ( site doesn't accept hot links unfortunately so you have to cut and paste). http://bags.0catch.com/1A_The_Derivation_of_the_Range_Estimation_Equations.doc |
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Bigdaddy0381
MODERATOR Georgia peach Joined: February/27/2007 Location: Georgia Status: Offline Points: 13680 |
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This is another awesome site that tells about mill-dots also. nice work on your site
BD
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P&Z Firearms , Pro gun cleanings and gun repair and wood refinishing.
Ecclesiastes 10:2 |
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Bags
Optics GrassHopper Joined: April/26/2007 Status: Offline Points: 24 |
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Thanks. Yes that is a good sight. My original paper is at the top of that sight under "An In Depth Study" .
Thanks Bags
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Bags
Optics GrassHopper Joined: April/26/2007 Status: Offline Points: 24 |
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Update: O.K. Here are the results of my phone calls to Leupold, Nightforce, Schmidt & Bender, U.S. Optics, S.W.F.A and Bushnell Optics.Before I get into my great conversation with U.S. Optics, here are the results: They all use “real” mathematical millradians, (which is 3.6 inches at 100 yards based on 6283.2 mils per circle) for their reticles. Except for one, they also all use “true” Moa (1.047 inches at 100 yards) for their reticle spacings. U.S. Optics, who were very helpful, say’s they make their scopes in real “mils”, but make most of their “moa” scopes in “shooters” moa (1 inch at 100 yards). They do sell a “true” moa scope also for those who want it. Their refurbishing of the Unertl scopes also reveled that the original Unertl scopes were in “real” mils (3.6 inches at 100 yards). That is how U.S. Optics makes their scopes now. Therefore, since my paper is for “Rifle” shooters, Snipers, Tactical shooters (and not artillery persons) I will change my paper to reflect only the “real” millradians and both “true” and “shooters” moa. I want this paper to be a one source, definitive, accurate guide to “mils” and “moa” for shooters and to finally put the controversy to rest. I revised my paperto reflect this.
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Bags
Optics GrassHopper Joined: April/26/2007 Status: Offline Points: 24 |
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I now have a hot link:
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medic52
Optics Professional Joined: October/05/2006 Location: Missouri Status: Offline Points: 893 |
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THANK YOU for the link... Owe you a Beer
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"The true soldier fights not because he hates what is in front of him, but because he loves what is behind him." G.K. Chesterton
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mattfetz
Optics GrassHopper Joined: April/04/2008 Location: Pa Status: Offline Points: 5 |
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Urimaginaryfrnd
MODERATOR Resident Redneck Joined: June/20/2005 Location: Iowa Status: Offline Points: 14962 |
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Good link. As for the "Long Range Shooting Simulation" CD mentioned above I have it and like it.
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"Always do the right thing, just because it is the right thing to do". Bobby Paul Doherty Texas Ranger |
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Clark
Optics Apprentice Joined: February/13/2004 Location: Near Seattle Status: Offline Points: 124 |
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The way I look at it 1 moa is ~ 1" at 100 yards, and ~2" at 200 yards.
A milliradian [ one thousandth of a circle divided by two pi] of is 3.6 inches at 100 yards. So an moa is 1" at 100 yards and a milliradian is 0.36" at 100 yards. My eye can see ~ 1 moa, so if a scope is fist focal plane, I can barely see the hatch marks on the tactical reticle at 1X or 2X if they are 1 moa. So my eye can barely see .1 milliradians with 7X or 14X I can see .5 milliradian marks on the reticle over the target on 2X magnification, but that is an all out eye exam effort. What is easiest for me is to look at the target with the range finder [A Lecia CRF1200 from SWFA and it works great], say it says 500 yards, then I look at my print out from Quicklaod that says with that bullet at that velocity, zero'd at 200 yards and the scope 2" above the bore, then I need 40" elevation or 7.8 moa. I then either aim 3' over the lung shot or I turn the elevation knob on the scope up 7.5 or 8 moa. |
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Clark
Optics Apprentice Joined: February/13/2004 Location: Near Seattle Status: Offline Points: 124 |
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That should be 0.1 milliradians is 0.36" at 100 yards, if this thing had an edit function. |
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rifle looney
Optics Master Joined: November/21/2008 Status: Offline Points: 2553 |
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Clark, you can edit using the post options at the right.
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Clark
Optics Apprentice Joined: February/13/2004 Location: Near Seattle Status: Offline Points: 124 |
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I do not think I get that function until I reach 50 posts.
I did write a poem: http://www.thegunzone.com/gunwriter.html
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Clark
Optics Apprentice Joined: February/13/2004 Location: Near Seattle Status: Offline Points: 124 |
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www.technika.nu
Optics Journeyman Joined: August/02/2005 Location: Sweden Status: Offline Points: 611 |
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I cant see your link Bags, have something happend to it?
What I belive mostly propble never understand with mil dot is that it's a metric system, and every use with mil dots combined with MOA, Inches and yards is more or less waste, slow, confusing and most of all stupid.
In mil is one meter at 1000 meter, or 10 centimeter at 100 meter.
30 centimeter at 300 meter etc.
Combined with 1 cm clicks (same thing as 0,1 mil clicks) makes math and use very much easyer.
The combination of Mil dots and MOA clicks is really awkward and a superior way of doing something wrong.
Technika
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Kickboxer
MODERATOR Moderator Joined: February/13/2008 Status: Offline Points: 23679 |
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Leaving the errors above out, if you hold 1.7 mils with a mil-dot scope you will be pretty much dead on. Just slightly under 1.75 mils. A mil-dot master can help significantly. I'm multiplying in my head here.
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Opinion,untempered by fact,is ignorance.
There are some who do not fear death... for they are more afraid of not really living |
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jonoMT
Optics Master Extraordinaire Joined: November/13/2008 Location: Montana Status: Offline Points: 4853 |
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Technika,
If I was depending solely on a reticle for ranging, I would absolutely go with a mil/mil scope. You're right: The math is much easier - easy enough to do in your head. But once I realized the need for accurate ranging required a rangefinder and custom (range-verified) ballistics tables it really didn't matter to me if the knobs are 1/4 MOA. |
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www.technika.nu
Optics Journeyman Joined: August/02/2005 Location: Sweden Status: Offline Points: 611 |
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Even if you not are using it for ranging, it's still better to use it metric.
For example if you fires and see in either your scope or if someone spotting for you see that you are .3 mils off.
That is easy to turn the turret 3 klicks, but what will you do?
Bring out the calculator from you pocket?
To use mildots with moa is like driving a formula one car on petrol made for mopeds, certainly not a way of optimizing things.
Technika
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jonoMT
Optics Master Extraordinaire Joined: November/13/2008 Location: Montana Status: Offline Points: 4853 |
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Technika,
I agree that it makes more sense to go mil/mil. However, to answer your question (and I admit it's just one scenario), I might do either of these: 1) Simply holdover .3 mils with the reticle 2) Compensate this way: There are almost 12 1/4 MOA clicks to a mil (11.63) so I can basically think of it as a 12:10 or 1.2:1 ratio. So if I'm thinking in terms of 1/10 mils I can just easily multiply 3 x 1.2, get 3.6 and quickly round that to the nearest 1/4 MOA click, which would be 4 in this case. Yes, there's some error but I have to round anyway. And it's not like it would be that much. A 1/4 click difference @ 500 meters is ~3.5 cm. Yes, it's still better to go mil/mil, but it's not that hard to convert 1/10 mils to 1/4 MOA. Maybe I find it easy because I've done a lot of woodworking and we still use the ridiculous 12 inch foot so I'm used to multiplying times 12 quickly. I really think what's most important is for shooters to get away from notions like 1 inch @ 100 yards or 10 cm @ 100 meters and just think in terms of angle, whether it be the ideal mil/mil or MOA. Jon |
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Kickboxer
MODERATOR Moderator Joined: February/13/2008 Status: Offline Points: 23679 |
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That's some fancy cipherin' jono.. |
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Opinion,untempered by fact,is ignorance.
There are some who do not fear death... for they are more afraid of not really living |
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www.technika.nu
Optics Journeyman Joined: August/02/2005 Location: Sweden Status: Offline Points: 611 |
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Jono
That is another way where the mil dot is so great, it's so easly translated to centimeters
1 mil at 300 meters is 30 centimeters.
1 mil at 525 meters is 52,5 centimeters...........
Technika
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