Rifle Scopes Leupold 6-18x mil-dot... but a 14x mil-dot reticle

[Humble284]

Ok my peeps... school me a little...

Here is the story: Got a deal on a Leupold 6-18x Mark 2 Mil-dot scope. Bright and sharp image, I like it just fine. Was ranging with it at know distances to test my estimation accuracy and got some wild numbers... figured it out after a phone call to Leupold. They put a 14x mil-dot reticle in the scope. When i was ranging with it, it was cranked to 18x. Ok, at 18x, multiply the final range calculation by 18/14 and you get the corrected distance... not great, but not a problem

This scope lives at 18x. Some have told me to dial it in to 14x and stick a knife in it, but that offends my sensibilities. It also offends me that Leupold would put their name on this scope with its inherent flaw.

Anyway, on to my dilemma. Since it lives on 18x, I have corrected my cheat sheets for the 18/14 factor. But I have noticed something spooky.

When I am using the mil-dots for hold over at a given zero, there does not seem to be a need for the reverse correction factor, i.e. 14/18. That bakes my noodle. This is a second focal plane reticle, which may or may not explain this effect, but I cannot reason through it.

When i use the mil-dots to range, I need the 18/14 correction factor. But, when I use the mil-dots for hold over, I don't.

I noticed this when I corrected my mil-dot hold over by 14/18 and the results were way off... but when I use the generic Sierra V6 mil-dot table, it is spot on.

WTF am I missing?

 

[Jason280]

Re: Leupold 6-18x mil-dot... but a 14x mil-dot reticle

No that this helps your problem, but not all scope manufacturers mil at max power. I believe some mil around 10x and a few others at 12x, depends on the manufacturer.

 

[pupdawg]

Re: Leupold 6-18x mil-dot... but a 14x mil-dot reticle

Your scope is only accurate at ranging with the reticle at 14x.

If you use the reticle for hold overs you don't need to convert anything to anything... you're just holding on over or under as long as you're on the same power.

The reason why you're running into problems is because you're trying to use the properties of a first focal plane scope with your second focal plane scope and that won't work.

And stop trying to range at 18x. Range at 14x then you don't have to do all that 18/14 stuff or whatever it is you're doing.

 

[Humble284]

Re: Leupold 6-18x mil-dot... but a 14x mil-dot reticle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: pupdawg</div><div class="ubbcode-body">If you use the reticle for hold overs you don't need to convert anything to anything... you're just holding on over or under as long as you're on the same power.
</div></div>

So lets stick with the quote above for now... The same power as what, the spec power for the mil-dot reticle? The confusing part for me is that with the scope cranked to 18x, the standard mil-dot hold overs work (coming from Sierra V6) even though it is a 14x reticle. A reason or explanation for not needing to correct when using the dots for hold over would be nice.

Let me ask it this way: In a first-focal-plane (FFP) mil-dot reticle, when you crank the power up, the reticle gets bigger, i.e. you are magnifying the reticle. In a FFP mil-dot would the hold over change depending on the power you dialed into the scope?

I am still learning about this long range craft, bear with me a little.

 

[Lindy]

Re: Leupold 6-18x mil-dot... but a 14x mil-dot reticle

I believe that what pupdawg was saying is this: Suppose you observe a shot which goes high by, say, 1.2 mils at some arbitrary power. If you correct your next shot by that 1.2 mil error, <span style="font-style: italic">without changing the power</span>, the correction will work. You measured it and shot the corrected value on the same power - so no problem.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">In a first-focal-plane (FFP) mil-dot reticle, when you crank the power up, the reticle gets bigger, i.e. you are magnifying the reticle. In a FFP mil-dot would the hold over change depending on the power you dialed into the scope?</div></div>

With an FFP reticle, the values on the reticle are correct irrespective on what power you're on. So, to use the example above, the 1.2 mil correction would work, even if you changed the power between the two shots.

 

[Humble284]

Re: Leupold 6-18x mil-dot... but a 14x mil-dot reticle

Ok, so is it a fluke then that Sierra V6 would spit out a spot-on mil hold over chart for my load that would work without correcting for the SFP reticle? Similarly, the 18/14 correction make the mils in my scope bigger at distance, i.e. 18/14 * 3.6" at 100 yards etc etc. How then could it be that the standard mil chart could give me accurate hold overs when the mils I am looking at represent a larger measure?

Perhaps I am over thinking this or I am missing a critical piece of info about optical ranging methods.

I do appreciate everyone trying to explain it. Hopefully, I have done a adequate job of asking the question. If not let me know and I will keep trying.

 

[hinkraka]

Re: Leupold 6-18x mil-dot... but a 14x mil-dot ret

I don't know about that program, but what info do you feed into it?

 

[BigBrother]

Re: Leupold 6-18x mil-dot... but a 14x mil-dot ret

What you need to do is determine your actual elevation adjustments for your load using the knobs at a given distance, *then* test the mildots against that.

As a newish shooter (I'm assuming?) you will find that ballistics calculators are seldom correct with the initial inputs, unless you truly know what you're doing and punch in all the small variables correctly, and even then I'm not 100% sure.

Mils are a rough substitute for those pretty little clicky things on your scope

. Use those, get your real data, and then you can draw proper conclusions.

 

[popeye089]

Re: Leupold 6-18x mil-dot... but a 14x mil-dot ret

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BigBrother</div><div class="ubbcode-body">What you need to do is determine your actual elevation adjustments for your load using the knobs at a given distance, *then* test the mildots against that.

As a newish shooter (I'm assuming?) you will find that ballistics calculators are seldom correct with the initial inputs, unless you truly know what you're doing and punch in all the small variables correctly, and even then I'm not 100% sure.

Mils are a rough substitute for those pretty little clicky things on your scope

. Use those, get your real data, and then you can draw proper conclusions. </div></div>

100% spot on with always test the data from ballistic calculators. Yes they are awesome tools and are usually very very close if not pot on, but always test. As an example say your RC from your programm is off by .5 moa at 800m that' a 4" difference guy. So relax, go over your fundementals and always do some equipment info recon before you assume anything about it. You know what they say about assumung right?LOL