[AmericanFreeBird]

I have a Leupold MilDot variable zoom scope. The manual says for variables to use a certain magnification for proper range calculations. For the 3-10X it says use 10X for the 4-14X it says use 14X, no mention of what mag to use with the 6.5-20X.

I have a mildot calculator that I bought from Dillon and tested the optics against an 18" line at 100yds. According to the calculator, at 100yds an 18" object should be 5 mils. I adjusted the mag until I had 5 mils and noted the proper setting for range determination.

Does this sound like I've got the right setting or should I call Leupold?

[craigz]

I would be very surprised if the reticle was not designed for use at the scope's maximum magnification.

[Skullboy]

From I what understand regarding Mildots and variable power scopes, is that you range on the highest power setting.Check out this link.It has a good explanation of mildots.
http://www.snipersparadise.com/equipment/optics/Mil-dot.htm.

I think the reason that you can't find the info on the 6.5 X 20 scope, is that particular scope is not common to sniping/tactical situations.The 3.5X10, and the 4.5X14 are the most common variable Tactical/mildot scopes in the leupold line.

HTH. SKBY.

[whoami]

20x should be correct. IIRC it has to do with where the actual wires of the reticle are located w/ regard to the focal plane. The variables were designed for it to work at maximum magnification.

Premier Reticles http://www.premierreticles.com/ has designed a Gen-2 Mildot reticle that places it in the proper focal plane so that mildot calculations will be correct throught the entire variable range. Apparently there was enough of an outcry for someone to do it. With the Gen 2, no matter what magnification, the mils can be used properly. I think it costs around $200 or so to convert an existing scope..

[AmericanFreeBird]

Well that's interesting, I guess the mildot slide rule I have is calibrated for another setting. Cause at max magnification it's nowhere near accurate. I guess I'll just have to test test test to find out if the reticle ranges are accurate.

Thanks all!

[Cal4D4]

I am sorta looking into the mil-dot thing also. One thing I read was that serious users will do like you did and calibrate the magnification to use against a known standard at 100 yards and maybe further out also.

[mpthole]

AmericanFreebird:

I also have the 6.5-20x50 LRT mil-dot scope. The mil-dots are calibrated for 10x. If you are set to 20x and try to determine the distance, you then have to double it.

For example: You have a 36" (1 yard) tall target. It takes up 2 mil-dots on your scope set at 10x. This gives you a 500 yard shot. Now, let's say you have the same thing except your set to 20x... 36" (1 yard) tall target, takes up 2 mil-dots. After running the numbers you come up with 500 again, but you have to double it, so its really 1,000 yards.

I know for a fact that I've read this somewhere in Leupold's literature. I'll see if I can track it down for you.

Ah HAH!!! I found it (http://www.leupold.com/resources/myinfo/abook2/abcard/33.asp?Per_ID=&ContextPer_ID=&VPath=/resources/myinfo/abook2/abcard/33.asp&FreeText=on&Abstracts=on&Key=2665_Y2003M1D14H20N44) :
The Leupold Answer Guide
Mil Dot Reticle
(snip)...
The Mil. Dot reticle is a range finding reticle originally developed for military applications. The space between dot centers subtends one milliradian(mil). One mil. subtends 3.6 inches at 100 yards or 36 inches at 1,000 yards. To use this system effectively you must know the size of the target.

Please note that your Mil. Dot reticle was calibrated to be used at one magnification. If your scope is a 3.5-10 the correct magnification is 10x. On the 4.5-14 use 14x. On the 6.5-20 use 10x, or double the distance determined on 20x. The use of any other magnification will yield inaccurate results.

Height of target (yards) X 1,000/Height of target (mils) =Range (yards)

[gk1]

Leupold's answer (http://www.leupold.com/resources/myinfo/abook2/abcard/33.asp?Per_ID=&ContextPer_ID=&VPath=/resources/myinfo/abook2/abcard/33.asp&FreeText=on&Abstracts=on&Key=2665_Y2003M1D14H20N42). The previous poster is correct; 10x is the correct magnification.

George

[AmericanFreeBird]

Well that makes my findings make sense also. I drew an 18" bar on my target at 100yds. Then using my mildot calculator figured out how many mils the bar should measure at 100yds eg. 5mil.

At 20X it was 2.5mil, so I adjusted the mag until I had 5mil and low and behold, 10X!

Thanks everyone I think we've solved it, if you're a prarie dog, this is NOT good news! :D