# NightForce NP 1 reticle

Discussion in 'Long Range Scopes and Other Optics' started by 1eye, Apr 7, 2010.

### Help Support Long Range Hunting by donating: 1. ### 1eyeWell-Known Member

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111
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Feb 8, 2009
5.5 x 22

Which formula to use calculating distance using the NP 1 , 1 moa. I have 2 different formulas ! (Example ) Using 11 inches and 1 moa. and 2.5 subtension ( marks )

11in x 100/ 1.0472/ 2.5 = 420 yds

11in / 2.5 x 100 x .995 = 440 yds

Which is the right one!

Thanks

2. ### kidcoltoutlawWell-Known Member

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339
Joined:
Dec 18, 2001
A 11 inch target is covered by 2.5 MOA 2.5 goes into 11 4.4 times then X 100 =440 yards.

Faster and more accurate than Mil Dots or I think so . You don't have to do target size by mil dot times 27.77.

I zero off of the very top of my NPR 1 you get more range before you start clicking,

Thanks,Keith

3. ### sscoyoteWell-Known Member

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1,271
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Feb 26, 2003
The 1st formula has the correct values. What you're saying in the second formula is that there are .995 inches per 100 yds. (for 1 MOA), and that is not correct. U must remember that each of those values has a unit designation that's assumed, and they must cancel correctly to get yds. i.e. in the 1st equation it's--

" x yds. / " / unitless value = yds. (inches (") cancels and u get yds. as the final unit)

(actually the same goes for the 2nd formula but my math isn't good enough to see where the (") values cancel to get just yds., but it must somewhere since that formula is just a rearrangement of the 1st one) .

To get as precise as possible with the reticle though u should subtract one line thickness since most of us tend to bracket a target between line stadia rather than from center of line to center of line (this then makes the reticle not a true MOA system...for rangefinding purposes).

So then according to the catalog the line thickness of the NP-R1 is .065 inches per hundred yds. (IPHY), which makes your 1st equation "more correct" as--

11 x 100 / 0.982 / 2.5 = 450 yds.

Although a measurment as small as the thickness of the fine lines of this NF may seem insignificant it can make a difference as range increases (30 yds. in this example). The way i look at it is u have to use the formula anyway so u may as well use it as accurately as possible.

Last edited: Apr 8, 2010