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# Help with a Mil-Dot Scope

10-28-2010, 08:11 AM   #11
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Thanks for the input ccd.

It's definitely the variety where reticle remain constant regardless of power, so i think second plane.

I will try again, but from memory i think the 333 multiplier worked on whichever power I used.

Dave

10-28-2010, 09:55 AM   #12
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Hi again,

i've confirmed that 333 works with all power levels.

using 1000 multiplier results in too great distances.

so back to the original question: could Tasco NOT be using genuine mildots?

would this affect holdovers and similar compensating actions?

dave

10-28-2010, 11:11 AM   #13
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Quote:
 Originally Posted by dave79 I recently bought a Tasco 2-6x32 Mildot scope. The formula in their instruction sheet has me puzzled. Can anyone comment on why they would suggest to multiply by 333 instead of 1000? Instruction sheet: (Height in metre x 333) / mils read = Distance in metre Everywhere on the web this formula is expressed as: (Height[in yards] x 1000) / mils read = Distance [in yards] It's as if this scope has its dots differently spaced and not like true mildot??? Anyone? Thanks.
The above is just a guess on my part, because I suck at math......

Which is why I resort to using one of these.

http://www.mildot.com

10-28-2010, 11:49 AM   #14
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Quote:
 Originally Posted by dave79 Hi again, i've confirmed that 333 works with all power levels. using 1000 multiplier results in too great distances. so back to the original question: could Tasco NOT be using genuine mildots? would this affect holdovers and similar compensating actions? dave
How have you confirmed it?

If the reticle is in the second focal plane you can not use the same formula, you are changing the size of the target in relation to the reticle as you adjust the magnification.

The easiest thing to do is to place a target of a known size downrange and measure it at various magnification settings. EX: 18" target at 100yds. This will tell you what the spacing is.
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10-29-2010, 11:51 AM   #15
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Hey ccd,

that's exactly how i confirmed, i took a known size object, put known distance away and observed how many mildots at each magnification level, from 2x to 6x.

plugging in 333 gives correct results.

increasing power requires dividing the result by appropriate power number, to account for larger picture on the same-size-reticle.

plugging in 1000 in the equation gives me distances that i know are just too long.

my comcern now is, unless there is a way to explain why 333 works, then would somehting like 'mildot' card work on my reticle?

i'm not sure that math will make sense. eg: if the card says compensate by holding-over one dot, and my dot is actually 3x the real mildot? is that possible?

thanks,
d.

10-29-2010, 03:08 PM   #16
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Quote:
 Originally Posted by dave79 Hey ccd, that's exactly how i confirmed, i took a known size object, put known distance away and observed how many mildots at each magnification level, from 2x to 6x.
So, what is the subtension between the dots at the various magnifications?
If you find a magnification level where the distance between mil-dots is 3.6" at 100yds then all the normal formulas and drop tables will work at that magnification.
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10-31-2010, 06:55 AM   #17
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Firstly, appologies to everyone for hogging the thread with my Tasco scope issue. I think I will just have to consider buying a better scope in the future.

In reply to ccd, I checked again...

I took your suggestion that I should see 3.6" @ 100 yards covered by one mildot. Sadly I didn't have so much space so I figured 1/4 of 3.6" at 25 yards should be the same. Let's call that "target area".

First problem: even at highest magnification (6x) one "mildot" on my reticle covers more than the target area. So this reticle is either faulty, or uses some other standard.

Of course as I reduce power, the reticle remains the same but target zone shrinks. Maybe if I could magnify more, eventually I would match one dot to the desired target area -- now I wonder if this scope has reticle printed for Tasco's 3-9x (more commonly seen online) but lenses only actually magnify 2-6x?

So out of curiosity I checked that 333 multiplier again, with known sizes and distances and found that the multiplier is not constant either, as I changed magnification.

Target size was 6" or 0.15m
Distance from target was 12.5m
Solving for multiplier M

@ 2x (0.15 x M) / 2.75dots = 12.5m
therefore M = 229

@ 3x (0.15 x M) / 3.75dots = 12.5m
therefore M = 312

@ 4x (0.15 x M) / 5dots = 12.5m
therefore M = 417

@ 5x (0.15 x M) / 6.25dots = 12.5m
therefore M = 520

So until I can purchase a new scope, I will set this scope to one power level only and learn how to get by. Bit of a bummer but maybe I will learn something accidentaly :-)

Dave.

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