Rifle Scopes Mapping a NF

[3bnRanger]

In the Optics FAQ regarding FFP vs. SFP glass Frank brought up a good point about mapping SFP glass and used a NF MLR as an example. Using a 22x model you can use the .5 mil marks as 1 mil at 11x. I have wanted to perform this with my 5.5-22 NP-R2 (MOA based reticule) and started reviewing my NF literature and found the following interesting:

At the ranging power of 22x my NP-R2 has a total of 40 moa worth of windage and 30 moa worth of elevation which would lead one to believe the values would be doubled at 11x...80 and 60 respectively.

However, NF literature states the reticule has 60 moa worth of windage both at the 10x and 15x settings and 40 moa worth of elevation at the 10x and 15x settings....how is this possible?

 

[KeithR41]

Re: Mapping a NF

What cant us your base? That'll make a difference. Also, your scope is probably not optically centered as mounted on the rifle. That will also make a difference in how much elevation and windage you have.

41

 

[head2h2o]

Re: Mapping a NF

Just by the definition of a SFP scope, I don't see how the reticle can have the same amount of windage and elevation at two different power settings. I think what NF is trying to say is that the reticle does not change size as the power is adjusted. They have it set in 5 MOA increments on the windage for the NP-R2 and 2 MOA increments for the NP-R1. This is good at 22X, but as you noted, decreasing the power to 11x doubles the distance between hash marks. Therefore you can measure / range at the lower power as long as you account for it in your calculations by noting the hash marks as 10 MOA and 4 MOA, but the intention is still for it to be a distance of 5 MOA or 2 MOA difference respectively when just talking about the reticle.

 

[3bnRanger]

Re: Mapping a NF

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: head2h2o</div><div class="ubbcode-body"><span style="color: #FFFF00">Just by the definition of a SFP scope, I don't see how the reticle can have the same amount of windage and elevation at two different power settings.</span> I think what NF is trying to say is that the reticle does not change size as the power is adjusted. They have it set in 5 MOA increments on the windage for the NP-R2 and 2 MOA increments for the NP-R1. This is good at 22X, but as you noted, decreasing the power to 11x doubles the distance between hash marks. Therefore you can measure / range at the lower power as long as you account for it in your calculations by noting the hash marks as 10 MOA and 4 MOA, but the intention is still for it to be a distance of 5 MOA or 2 MOA difference respectively when just talking about the reticle. </div></div>

This was my thinking as well....I suppose I will have to contact NF for an explanation. Who knows, maybe it was a misprint and they will reward me for my attention to detail

 

[gstaylorg]

Re: Mapping a NF

The manual lists changes in the reticle line thicknesses at different magnification that are proportional to those listed for the hashmarks themselves. Can't see how that's possible. If you contact NF, let us know the answer...this is intriguing.

 

[kombar]

Re: Mapping a NF

The answer is an easy one. Those values listed on the PDF are simply the values of the NP-R2 reticle as offered in DIFFERENT scope models.

It's not saying you'll have 60 MOA total windage at 15x, it's saying that the 3.5-15x model has 60 MOA total windage at its ranging power (15x). Same thing with the 2.5-10x.

So all it's saying is that your scope has 40 MOA windage and 30 MOA elevation on the reticle at the ranging power (22x). You already know what to do to find other values: halving the magnification doubles the reticle subtension, etc.

 

[gstaylorg]

Re: Mapping a NF

Thanks Kombar. As soon as I started reading your answer to the question, it hit me, because I've been through the same thing before with the NF reticle manual. Nothing like the cold realization that you're (meaning me) a complete <span style="font-style: italic">dufus</span> for not catching something as simple as that (LOL).

 

[3bnRanger]

Re: Mapping a NF

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Kombar</div><div class="ubbcode-body">The answer is an easy one. Those values listed on the PDF are simply the values of the NP-R2 reticle as offered in DIFFERENT scope models.

It's not saying you'll have 60 MOA total windage at 15x, it's saying that the 3.5-15x model has 60 MOA total windage at its ranging power (15x). Same thing with the 2.5-10x.

So all it's saying is that your scope has 40 MOA windage and 30 MOA elevation on the reticle at the ranging power (22x). You already know what to do to find other values: halving the magnification doubles the reticle subtension, etc. </div></div>

Wow, I should have caught that one. It's good for my ego every now and then. Thanks.