Mil v MOA. Did I understand it?

Geometrically, there are 6283.185... mils around a circle.
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No - actually there are 6.282722513 ...(to infinity) radians because Pi is used as part of the calculation (circumference of a circle) and Pi is an irrational number (cannot be expressed as a ratio of two integers) and will go to as many places as you care to carry it.

The number of radians in a circle (6.283) is rounded UP to 6.283 from 6.2827.

"Milli" is commonly used in units of measurement to denote a factor of one thousandth.

So, a "milliradian" is 1/1000 of a radian meaning - you take the previously calculated 6.283 and multiply by 1,000 = 6283 to get the number of radians in a circle. 6283 is the correct number to use as it has been arrived at by rounding up from the 1/10,000 decimal place.

I'm surprised you didn't point all of this out just to add more confusion to the simple process of using a Mil marked scope...

However, all of this is just like saying you can't accurately calculate the circumference of a circle because Pi is part of the calculation (2 x Pi x R).

You can never get the real measurement because Pi goes to as many places as you'd care to carry it out - but, after 0.0001 do you really care, except in specialized scientific or manufacturing applications?

If it's accurate to 1/10,000 do you need more for practical usage for aiming a rifle?
 
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You take your reading at that magnification as directed by the manufacturer, do the range calculation, and then zoom the scope to whatever magnification you need for the shot.
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Actually no, I just push the button on my Nikon IRT, and I'm done with it.
 
but if I ever get my behind into gear and get my hunting permit, I will be in the great unknown
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did Estonia suddenly grow Alps I was unawere of:D

if you zero your rifle with a slight "oversight" you can shoot out to hunting ranges with the same hold

don't overthink it

don't you have a semi auto 308 or a 792x39 or something for the pigs? driven hunts are more point and shoot then sniping
 
Its good to know all this stuff.Some have presented it very well,but,to a degree the discussion seems to be unnecessarily competitive. The minutia may be in the spirit of accuracy,but it muds up the water.

Mr Pond has a plain Duplex. No grads,no dots. AFAIK,he lacks even a factory spec.
So what difference does it make? All that is necessary to use the knobs is a common unit,reticle to knobs.All that is necessary to range is a common unit reticle to target size.

Who cares if the duplex is defined as 6 in for MOA knobs or 15.24 cm for mil knobs? If the knobs are 0.1 equestrian "Hands",call the duplex 1.5 hands.
I forget,is a cubit 16 inches?Great news!!If you have 1/40th cubit grads on your knobs,its .4 MOA.The 6 in reticle is .375 cubit.You can work with cubits!And,amazingly.1 hand equals .4 MOA too!! So,.1 hand = 1/40th cubit!!and,its real close to .01 meters,.394,.
For a plain DUPLEX
It does not matter. one "DUPLEX " is my unit of measure to range.At what range does one DUPLEX equal my target size? 300 yds? Fine!!400,Fine!!200? Works for me!!

If its 300,and the target is twice the duplex,the range is 150.If the duplex is twice the target,its 600.

While the argument over the definition of Mil radian is cool for knowledge,it a plain duplex.

The same basic technique is described either in the old RANGER or INFANTRY handbooks using the width and height of the of the M-14 front sight features.
This ain't news.
An aside,despite the technical def of a mil rad,(no,I'm not a Veteran) I have had a little training setting up aiming stakes and running an 81 mm Mortar.
That 6400 mil thing works pretty well.Its about "bracketing",6400 is easy to cut into 1/4,or 1600.Half of that is 800,half is 400,half is 200,etc.Hard to do with the true milrad number.
Its also sort of a machinist standard.A dividing head(or rotary table) takes 40 cranks for 1 rev.Put a 40 hole plate on,its 1600 divisions.An Arty mil is1/4 that.

Most all well equipt machine shops had dividing heads.Its a way of thinking
 
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Well, I will be shooting my Oryx OCW sets this Friday (weather allowing) and whilst there I will take the time to take some measurements from the different components of my reticle and from there work out a rudimentary ranging system.

I'm also going to dig out my Burris manual and parts to see what it says and what the turret sleeves show.

I will say that my reticle is a constant source of puzzlement. By all accounts, based on what I've seen online, it should not exist!! I have no idea exactly which reticle it is!!

May have to write to Burris and ask them and see if they have data available for what the different dimensions equate to at 100m.
 
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I'm a bit of a knucklehead and not a habitual long-range shooter--but if it were me I would also be concerned about testing the ammo used to get a reliable ballistics table for the bullet's velocity and drop and use that as a starting point if I were really thinking about taking long shots. As the range got long enough to where the bullet's trajectory really starts to "rainbow" I wouldn't have enough confidence in duplex bracketing target size guesstimation and would probably need a good laser range finder. And I use Strelok a lot to help reduce the stress on what few functioning brain cells I have left. :)
 
Right, well I have been in touch with Burris and their rep has been pretty helpful although neither of us is much the wiser.

First thing I have leanrt is that I appear to have an atypical scope!! It seems that my reticle is indeed a Plex and that is not usual for the XTR scope!!
It is also not usual to have numerous turret sleeve options in the pack.

This also means that none of the listed subtensions for Plex reticles in the Burris database can be matched to my rifle!! :rolleyes:

I have a unique, mongrel Burris!! Should I be happy about that? Dunno!! :confused:

(Those sleeves actually seem to have nothing to do with MOA/MIL. My factory fitted ones are graduated 0-16 clockwise, whilst the spares are graduated 0-8 down both sides where the 8 and the 0 are at 180 degrees to one another: no idea what they are. No idea where a total of 16 possible graduations come in, either!! :()
 
Sounds like an "immaculate conception" product--could be a collector's item. : )

As a rank amateur unprofessional shooter here is what I would do:

1) first off, do you want to really keep the scope or not? forget about the ranging system--are you happy with the glass itself, clarity,eye relief, field of vision etc? If not--move on to a different scope (or get Burris to exchange it).

2) If you do like the glass itself, then determine the inherent precision of the scope. Regardless of the reticle and turret markings, choose two or three cardinal distances (say 100 and 200 meters or yards) and using ammo of known consistent velocity and drop (meaning use the best you can, preferably chrono'ed). Shoot several groups at different elevations settings at each distance--all you are really trying to determine is whether or not the scope has a high degree of repeatable precision based on the shifts of POI. Depending on how "granular" the turret clicks are and how flat shooting the ammo is, you may need more than one click and/or move the distances between the comparison targets.

3) If the groups do in fact show repeated precision--then it's time to do the math to figure out what the ranging system and reticle really is. This is where I pull the bail and leave the method to the expert more experienced shooters who have already commented on this thread--but the main point being that if you have a known cartridge velocity and drop and two reference targets--it doesn't matter if the scope system is minute of star trek klingonese, you should be able to figure out what the real system of measurement is, the most important thing being is it repeatably precise.

Then again--I could be totally wrong! : )
 
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I have a calculator (In Excel) that I created that will convert:
Mil to MOA or Inch
MOA to Mil or Inch
Inch to Mil or MOA

And will also tell you your true Reticle Subtension measurement value for either MIL or MOA on a SFP scope based on the magnification setting that gives you your true measurement (look at your owners manual, but most scopes are max magnification will give you a true 1 MOA or MIL) and the magnification setting you have the scope set to...

Comes in handy for scopes that have MOA adjustments with a MIL reticle and for SFP scopes with either MIL or MOA reticle...
 
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That's cool precision--somewhere floating around on the forum somebody has a formula for calculating velocity based on drop to known target distance. Would be cool (maybe already exists?) to have a resources page where people can post their pages (and of course get credit).
 
I should say I am pleased with the scope. It performs well.

Looking back, stronger magnification would have been nicer, but I don't think I will be shooting massive distances anyway, despite what I'd like. I just don't get the chance.

In every other respect I am happy, although I have next to no other experience of scopes beyond it, a Nikon Prostaff and a 1-4x Leupold.
 
Pond, that sounds like your sleeves are the options for zero at point blank or 100 where you only dial one way for targets farther out and come back down to zero, or for a zero at longer range like 300 where you need to dial both ways depending on whether your aiming closer or farther away.
 
Pond, that sounds like your sleeves are the options for zero at point blank or 100 where you only dial one way for targets farther out and come back down to zero, or for a zero at longer range like 300 where you need to dial both ways depending on whether your aiming closer or farther away.
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That is a good point. The factors of 4 makes sense now, also: that would be 2MOA either way. There are also graduations on on the turret body, under the sleeve, that also allow for "return to zero".

Now, I just need to decide which of my loads I'm going to zero for and at which distance!
 
For target shooting, you should have a sight setting recorded in your notebook or taped to the stock for each range available. The tabulation should be for your most accurate load.

For hunting, I would zero on the "point blank range" system. Depending on the caliber and load, that will give you a killing shot at something 200-300 yards. For me, in a field position, no sighter shots, that is far enough.
I know there are long range hunters using reticle features or rangefinders and ballistic charts, but I am not one of them.
 
I used to love being able to hit hard at 1000 yards. As I get older I find hitting a mini ram at 200 yards with the 22 oddly more satisfying.
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Hand gun shooting at 100 is VERY satisfying (or very frustrating) lol.
 
My handgun shooting hasn't been satisfying since 1995. Much more difficult to offset age with high-grade equipment shooting handguns.
 
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