February 14, 2013, 07:06 PM  #1 
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Join Date: January 19, 2013
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Scope adjustment in MRAD
Can anyone tell me how the conversion is with a scope that adjusts in MRADs to MILs,
Im looking at the Vortex PST 624x50 EBR1 MRAD http://www.vortexoptics.com/product/...eticle/reticle I dont understand the MRAD Adjustment Graduation .1 Travel per Rotation 5 MRAD Max Elevation and Windage 19MRAD Im a Newbie and would like if someone could put this in words i can understand... Im used to the MILDot with 1/4 MOA Adjustments Hope this isnt a stupid question any input would be appreciated... Thanks 
February 14, 2013, 07:22 PM  #2 
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1 milliradian = 3.438 minutes of angle, so 0.1 MRAD = .3438 MOA
Each 0.1 MRAD graduation is a little more than 1/3 MOA. 
February 14, 2013, 07:49 PM  #3  
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A mil is nothing more then 1000th of a Radian. To find out what a radian is you take the length of the radius of a circle. Then from the point where the radius hits the edge of a circle, measure that the same distance along the circumstances, then back to the center of the circle, making a triangle with three equal lines each of which is the length of the radius. Now you divide that triangle by 1000 and that gives you milradians, milrads or Mils. Scopes normally come with MOA or mil adjustments. With a MOA scope you get 1/2 or 1/4 or 1/8 MOA clicks with 1/4 being the most common. Mil adjusting scopes come in 1/10 mil clicks. With the MOA scope, each click moves the point of impact 1 inch (to be more precise, 1.047 inches) 1/4 click will be 1/4 or .25 inches. A .1 mil click will move the impact 1/10 of a mil at 100 yards. So if 1 mil = 3.348 inches, then .1 mil will move the impact .3348 inches. Since its simpler to say and remember 1 MOA is an inch, then 1/4 MOA is 1/4 inch, THEN we can also make it easy to say .1 mil is 1/3 inch at 100 yards (.3348 is pretty close to .333 1/3) The real formula is "kiss" (Keep it simple stupid) no offense to anyone,thats the expression. Yes I know its not exact, and many people chime in and say its not 1 inch its 1.047 inches. Thats true, regardless what we say, we all think in inches or "1" not "1.047. But if you were to actually measure the clicks on your scope, even expensive ones you'll find out they aren't accurate either. They will be a little more or a little less then 1.047. The same thing with mils and a 10th of a mil. 1/3 of a inch is close enough and probably every bit as accurate as your scope's clicks. Don't believe me, Take a 4 ft piece of paper, draw a line down it with an aiming point at the bottom. Zero your rifle to hit that aiming point. Then count up clicks and shoot, watch as your bullet impact moves up the line. You'll find they don't move exactly 1/4 inch or 1/10 mil. Also you'll find that the higher you move up, the different each click will be, up or down. You'll also see the impact drifts left to right of the line. It may be the scope, it may be the rifle, it may be the shooter or it may be a combination of each. That's why its critical to zero your rifle and write it down in a data book. Use a BC Program but confirm it by shooting, WRITE DOWN the corrections. No zero at any yardage is correct until you shoot it to confirm it. So back on topic. 1 mil is 3.348, 1/10 mil click is 1/3 inches. and 1 moa is 1 inch , 1/4 moa is 1/4 inch Forget the 1.047 and forget .3348, you'll never see the difference on target.
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Kraig Stuart CPT USAR Ret USAMU Sniper School Oct '78 Distinguished Rifle Badge 1071 Last edited by kraigwy; February 14, 2013 at 07:56 PM. 

February 14, 2013, 07:55 PM  #4 
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kraigwy is right. It's actually 3.438 MOA per MRAD, not 3.348, but that's still close enough to 3.333 that you can use the "onethird inch per .1 MRAD at 100 yards" approximation that he suggested.

February 14, 2013, 08:01 PM  #5 
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Thanks for all the info, i appreciate the help,,,
Id like to ask a 2nd question about focal plane, for shooting out to 1000yrds. 1st focal plane or 2nd focal plane? Is this moreless a personal preference, im pretty sure i understand how they work with the retical staying the same with a 2nd focal plane, but only being able to range at high power, and 1st plane retical increasing with power and ranging at any power but wouldnt it be more difficult to make a more precise shot with an increased retical??? 
February 14, 2013, 08:18 PM  #6  
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Quote:
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Kraig Stuart CPT USAR Ret USAMU Sniper School Oct '78 Distinguished Rifle Badge 1071 

February 14, 2013, 08:36 PM  #7 
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1st focal plane. That way you can perform accurate ranging as well as accurate holds without worrying about your level of magnification.
A proper understanding of holds is key for any type of shooting that doesn't take place off of a bench at absolute known distances. A first focal plane scope can allow you to make measured holds at any magnification level, on a second focal plane reticule it's guesswork unless you're at max power.
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