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MOA or MRAD?

This is a discussion on MOA or MRAD? within the Modern M14 forums, part of the M14 M1A Forum category; Originally Posted by MikeM0331 It might just be my phone, but this was hard to follow (format). Yeah, it reads better on a computer. Originally ...


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Old April 24th, 2020, 11:51 AM   #46
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Quote:
Originally Posted by MikeM0331 View Post
It might just be my phone, but this was hard to follow (format).
Yeah, it reads better on a computer.

Quote:
Originally Posted by MikeM0331 View Post
As far as I know, rifle scopes that use mrad all use true mrad (6283 in a full circle).
Even a true milli-radian is not exact, as the 1/1000 of the range is based in the arc subtended by the angle not the straight line distance. But that difference is beyond negligilble.

1 mrad at 1000 inches =

straight line - .999 inch
arc - 1.000 inch

Quote:
Originally Posted by MikeM0331 View Post
I would like to add before it comes up (unless I already missed it), because ‘mericans think [in] freedom units, you can shoot on ranges built in yards with mrad scopes. Mrad is not tied to meters.
In some ways it is simpler than MOA. An mrad is 1/1000 of the range, just keep the units consistent.

1 mrad =

1 inch at 1000 inches*
1 foot at 1000 feet
1 yard at 1000 yards
1 meter at 1000 meters
1 mm at 1 meter
etc...

________________
* 28 yards, and by the way, that's why machine gun qualification was done on a 1000-inch range.)

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Old April 25th, 2020, 04:18 AM   #47
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First focal plane MRAD here. Much easier for me to figure on the fly and the first focal plane works great at measuring. As long as I hit paper at 25 yards I can measure and set turrets and be dead on with 2nd shot. Rezero turrets and install dead stop shims. Dead on in 2 shots.

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Old April 25th, 2020, 12:10 PM   #48
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I also use Strelok and love it. It's free. I have an iPhone. Don't know about Android. Have if programmed for all my bolt guns. Their database for scopes and ammo is amazing.

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Old April 30th, 2020, 05:23 PM   #49
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Originally Posted by lysander View Post
Are we talking "Milli-radian" (Mrad, or 1/1000 of a radian) or NATO artillery "mil", 1/6400 of a circle?

(Or Russian mils = 1/6000 of a circle)

Oh, and, 1 MOA at 100 yards is 1.047197536.... not 1.046666.

One military "mil" is 3.534291... inches at 100 yards (or 3600 inches). So, using the round-offs of 1 inch at 100 yards for MOA, or 1/1000 of the range for mils, will introduce a small error that grows with range. It is just that the two errors are in the opposite direction.

.Range . . . . . . . . . . . . Actual subtend . . . . . . . . . . . . . . . . . . . Round off subtend mil . . . . . . . . . . . . . . . . . . . Error
(yards) . . . . . . . . MOA . . . . . . . . . . . . . . .mil . . . . . . . . . . . . . MOA . . . . . . . . . . . . . mil . . . . . . . . . . MOA . . . . . . . . . . . .mil
100 . . . . . . . . . . . 1.047" . . . . . . . . . . . . 3.534" . . . . . . . . . . . 1.00" . . . . . . . . . . . . . 3.60" . . . . . . . . 0.047". . . . . . . . . . -0.066"
1000 . . . . . . . . . . 10.47" . . . . . . . . . . . . 35.34" . . . . . . . . . . .10.00" . . . . . . . . . . . . 36.0" . . . . . . . . .0.470". . . . . . . . . . -0.657"
2000 . . . . . . . . . . 20.94". . . . . . . . . . . . 70.69" . . . . . . . . . . .20.00" . . . . . . . . . . . .72.0" . . . . . . . . . 0.944". . . . . . . . . . -1.314"
3000 . . . . . . . . . . 31.41" . . . . . . . . . . . . 106.0" . . . . . . . . . . .30.00" . . . . . . . . . . . .108.0" . . . . . . . . .1.416". . . . . . . . . . .-1.971"
4000 . . . . . . . . . . 41.89" . . . . . . . . . . . . 141.4" . . . . . . . . . . .40.00" . . . . . . . . . . . .144.0" . . . . . . . . .1.888". . . . . . . . . . .-2.628"

Of course the only stuff shooting direct fire out to 4000 yards are tank guns, and they're shooting a tank-sized targets so 2-1/2 inches is a negligible error.

For riflescopes, a mil is 1/1000th of the distance, meaning that there are 1000x2xPi milliradians in a circle. I'm not sure why people bring artillery mils into the equation but there's also going to be that guy.

A Minute of Angle is equal to:

(2xPixR)/(360x60)

At 100 yds, or 3600 inches, this is:

2xPix3600/(360x60) or 2xPi/6 inches at 100 yds.

Pi is 3.1415926535to the first 10 characters, or 3.141592654 rounded to the first 9 characters.

3.141592654x2 = 6.283185308/6 = 1.0471975513(repeating).

If you use 3.14159x2/6 you get 1.047196666666667

If you use 3.14x2/6 you get 1.046666666666667

For the purposes under which a minute of angle is used, 1.047 is accurate enough.

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Old May 1st, 2020, 12:10 AM   #50
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...For the purposes under which a minute of angle is used, 1.047 is accurate enough.
Especially if you are shooting at gongs or folding targets as I do.

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Old May 2nd, 2020, 10:58 AM   #51
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Originally Posted by Ikeman83 View Post
For riflescopes, a mil is 1/1000th of the distance, meaning that there are 1000x2xPi milliradians in a circle. I'm not sure why people bring artillery mils into the equation but there's also going to be that guy.
Why? Because whenever I hear "mil", I think 1/6400 of a circle. All the fire control calculations in artillery where in 1/6400 circle mils, accuracy requirements for howitzers are in 1/6400 circle mils, the T&E for a .50 cal was in 1/6400 circle mils, the graduations on the little protractor they gave us for land navigation was in 1/6400 circle mils, the compass was in 1/6400 circle mils . . .

Habit.

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Old May 2nd, 2020, 05:43 PM   #52
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Personally, I think it depends on your training and life. Example: My grandfather who was a mechanic can look at a bolt and tell you what size it is, if its standard. He hated import cars because he thought in standard, lol. Because I built rat rods and cafe Racers, working on Hondas, Yamahas, and Kaw's, I can look at a bolt and tell you what MM it is, he couldn't, but I couldn't guess standard to save my life.

If your military or ex, M-rad all the way, and you can learn that way, too. If you hunt with military guys, maybe it's the best way to go for clear communication.

For me, though, its MOA, because I've spent half my life in construction. Commercial door is 36" opening, CMU block is 8x16, license plate is 6x12, shoulders of man=16, belt to top of head is 30, fences are 8 foot sections with 6x6 posts, etc. Now, I'm sure you won't find cynder blocks laying in FL wild, well, maybe, lol. But the point is that I can look at things like brush, or a tree and their size in relativity to other things around them and guess fairly well, putting MOA scopes, or close size in inches, to good use. Or, when in a hunting area, measure things around you, we have a ton of sabal palms in piggy areas, what's the average size? 3'? 4'? I dont know, but I should, lol. But sitting here on my porch with a bourbon, they usually come to my half way up my torso, I'm 67 inches tall, minus half my torso and head, so 67-15= 52, so yeah, they're about 4.5' tall, give or take. See that? Again, no idea in Mil, lol.

Of course, if you have a range finder, none of that is an issue unless there are size limitations. Like in FL, where the deer has to have 5 inches of antler? I think? Let's say that's true. So, even with a range finder, you see the deer at 200 yards confirmed, what size are the antlers if it fills 10 MOA VS 3 MIL ( I know they arent the same size), but 2 drinks in I can tell you its antlers are 5 inches tall, and I bet I could find a tree or something else around if I had time to confirm it. MIL? Again, dunno, too lazy to break out my App and calculator, lol. So, I'll stick with MOA.

Also, in terms of thinking, MOA is easier for me when using SFP scopes. Have a Leupold 3-15, easy, @7.5 power an MOA is 2 MOA, @3 power 1 MOA is equal to 5, etc. This is easy, to me in terms of MOA. but honestly, this part really is a whole new topic, like SFP vs FFP.

If your asking this question because a scope you like only comes in MIL, dont be discouraged, as others noted, you can just do that math in your head once figured out, if your like me and dig inches. I have a Leupold VXR in SPR MRAD, was pissed I didnt pay attention to that, as each "marker" in the reticle equals about 8.5 MOA @4 power!!! Fear not, may not be good for ranging, but oddly, alot of subsonics equal roughly a 8.5" drop for every 50 yards, lol. So it's a decent BDC for subs. You can utilize ideas like that to make a reticle work, with range finder in tow.

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Old May 2nd, 2020, 06:10 PM   #53
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Why? Because whenever I hear "mil", I think 1/6400 of a circle. All the fire control calculations in artillery where in 1/6400 circle mils, accuracy requirements for howitzers are in 1/6400 circle mils, the T&E for a .50 cal was in 1/6400 circle mils, the graduations on the little protractor they gave us for land navigation was in 1/6400 circle mils, the compass was in 1/6400 circle mils . . .

Habit.

That's interesting, but you're firing a rifle, not an artillery piece.

With rifle scopes, a mil is a measure equal to 1/1000th of the distance away from you.

I don't bring degrees Kelvin into discussions of how hot it is either.

A mil in a scope is going to be 10cm/100m, or 0.36" at 100 yds.

It's a great measure.

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Old May 2nd, 2020, 06:35 PM   #54
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I will add my 2 cents to this discussion if you all allow me...
I started out shooting deer with any old cheap scope I could afford and they were 1/4" to 1/2" 'clicks'... So that is where I come from...


Started shooting my M1A with a fixed SWFA 10X Mil/Mil that got me thinking...
Shot my best ever to date 10 Dot score back in 2018 using a SWFA 3-15 FFP Mil/Mil...
Been trying to beat or match that score and have been trying MOA/MOA scopes for their 'finer' click adjustments to no avail...


IMHOP it does not matter what you use or like but one must master the shooting fundamentals FIRST!


Master your shooting fundamentals first!


Then worry about Mils or MOA first or second focal plane!

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Old May 3rd, 2020, 07:38 AM   #55
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Too many big words for this country boy to unnerstan

I get both moa and mil but remember, kids. This is America! Make MOA great agin!

I hope y’all know I jest. Whichever between the two is easier for you? Go with it.

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Old May 3rd, 2020, 08:31 AM   #56
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Quote:
Originally Posted by Ikeman83 View Post
A mil in a scope is going to be 10cm/100m, or 0.36" at 100 yds.
It's a great measure.
..........a yard at a thousand, a foot and a half at 500
But yeah, a quarter of a MOA is finer than a tenth of Mil
meh


Last edited by stoky; May 3rd, 2020 at 09:06 AM.
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Old May 3rd, 2020, 09:07 AM   #57
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Quote:
Originally Posted by stoky View Post
..........a yard at a thousand, a foot and a half at 500
But yeah, a quarter of a MOA is finer than a third of Mil
meh

A 1/4 MOA is a pretty common adjustment increment for an MOA scope, but mil scopes are in 1/10th Mil increments.

So, while 0.26" at 100 yds for 1/4 MOA is finer than 0.36" at 100 yds for 1/10th mil, what matters is the maximum correcting offset per click. In other words, if I make a click, what's the most that click will be off?

With a 1/4 MOA turret, that deflection is 0.13" at 100 yds, or 1.3" at 1000 yds. With a 1/10th Mil turret, it's 0.18" at 100 yds, or 1.8" at 1000 yds.

While that's a finer increment, it's a difference of 0.05" at 100 yds or 0.5" at 1000 yds.

If you think that you're going to be making corrections that are so fine at 1000 yds that half an inch of courseness is going to make a difference, you should probably stop reading this forum and go pick up your 1st place F-class trophy.

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Old May 3rd, 2020, 09:23 AM   #58
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wuz thinkin of that RCH over a third of an inch, an irrational number
...............................shoulda waited for the Irish coffee to kick in


Last edited by stoky; May 3rd, 2020 at 09:40 AM.
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