# More NP-R2 photos

Discussion in 'The Basics, Starting Out' started by Dave King, Jun 5, 2003.

1. ### Dave KingWell-Known Member

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Okay, let's try this again.

Forget about the shingles and leaves...

Here's a painted, calibrated device...hi-tech too.

The plywood has 4 inch black (vertical) areas, 10 inch black horizontal areas...the rest you can divine from the reticle.

I took pictures at 3 power settings.

I discovered after some head scratching and steel tape verification that the LASER actually reads 100 yards at 100 yards.

Note: it's difficult to see the LCD screen on the back of the camera in sunlight so these images are a poke-and-hope set of "quality".

Let's discuss how to use ALL of the available features of this reticle. I believe S1 is probably more knowledgable than most here on this so... S1, if you'd be so kind to help out and get us started.

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3. ### Michael EicheleWell-Known Member

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A quick way to use that reticle as a range finder is as this: Size of target in inches divided by MOA * 100 = range in yards. Ok, first, as S1 stated at full power, the hash marks on the verticle line are 2 MOA. Lets say you are looking at the cross section of a deer (18") with the crosshair on his back and the 3rd hash on his belly is 6 MOA. this would meen that he is 300 yards away. 18" / 6 = 3 * 100 = 300 yards.

4. ### SheldonWell-Known Member

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What I'm really interested in is:

What kind of truck is that? Looks COOL!

5. ### BrentWell-Known Member

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R2 class is now in session!!

Nice pics Dave. Perfect setup too! I'll go with the 100 yard range and the scope settings in the order that S1 said too.

"Half" the Size of Target (inches)
__________________________________ x 100 = Range (Yards)

Size Target (lines)

Here's an even simpler way that S1 shared with me a while back for ranging, keeps the number smaller for easier math in the head.

One more tip for ranging while using the horizontal ticks, is that you can break down the nearest to center 5 MOA tick mark to 4 MOA because the vertical tick mark sticks out 1 moa, just helps break down the 5 to 4 to 2 to 1 and so on if you need to... a simple reference.

I'm savin my brain for harder ones now Dave. You'll be doing all them with it on 22x right. Thanks for the fun practice Dave!

6. ### Dave KingWell-Known Member

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Okay!

This is my first NP-R2 and I'm in the learning mode. First incorrect assumption on my part is that the scope is calibrated at the now infamous tick mark (11 power). (This was the reason for this series of photos...sort this thing out.) I believe I made this leap due to my use of the Leupold variables with MilDots, not an excuse just a statement/observation.

The distance is indeed 100 yards + or - verified by the LASER and twice checked (once by steel tape (at 298 ft) and once by measured cord (at 300 ft)).

The picts are simple enough, 5.5, 11 and 22 power as derived by others.

Brent thanks for the clarification in the other thread on the calibration being a 22 power.

Sheldon That's my hunting/beater/work truck. It's a 2002 Chev 2500HD, 8.1-liter OHV V8 with cast iron block 340hp @ 4200 455ft-lbs of torque at 3200 rpm. It has the ML6 (ZF S6-650) 6-speed manual transmission, 4.10 gears. It does NOT have limited slip differential and is a pain-in-the---- in snow, rain, ice, wet or dry grass, chicken guts, road kill possum or anything else slippery. I often need to switch to 4 wheel drive to get the thing to do anything other than spin one rear wheel when trying to move from a dead stop if not on dry pavement. There are no extra creature comforts, manual windows and door locks, bench seat, no fold down center console, no extended cab, no carpet. It has a Meyer's plow frame on it that hangs so low that I can hit frogs crossing the road and neighborhood speed bumps cause a nice shower of sparks. It's a great truck other than that...it'll pin your head to the rear window on acceleration and cause you to stop at nearly every gas station (13 mpg). I've had it since last fall (Sept 2002) I believe and have a little over 22,000 miles on it. The tires are still the stock Firestone - "May Pops" but I'll get rid of them soon. I don't wash it and it has mud and grime on it from most roads as far off as Georgia and Alberta (oops! probably should say that...someone may want to quarantine the thing for a Mad Cow (BSE)prion check).

Back to the NP-R2

Okay.... we can accurately range with the thing (providing we know the power setting for reticle calibration). (target size in inches / M.O.A. * 100 = range in yards)

What else can we do with it?

We can measure with it providing we know the distance.

Deer/Elk antlers size = distance in yards (LASER) / 100 * M.O.A. = target size in inches.

We can use it for hold-offs.

Stinking 308 Win shooting old government 173's. Zero at 100 yards, come-up to 200 yards = 2 M.O.A., come-up for 300 yards is another 3 M.O.A., come-up for 400 yards is another 3.5 M.O.A. and come-up for 500 yards is still another 3.5 M.O.A.
Leave the scope set at 100 yards (an 22 power) and shoot the 500 yard target by centering the 6th tic/line down (12 M.O.A.)

What can we do with the reticle by changing the power setting?

How do we get a calibrated lead hold on a mover traveling 30 mph at 90 degrees, 350 yards, standard 308 & Gold Medal 175's?

[ 06-06-2003: Message edited by: Dave King ]

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8. ### Dave KingWell-Known Member

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S1

I've haven't seen this 4) Know how to convert MPH of target to FEET PER SECOND: MPH divided by 7 multiplied by 11 In this example:
30/7 = 4.3, 4.3 X 11 = 47
before. This makes 1 mile per hour (mph) = 1.57 feet per second (fps), I've always seen 1.46 fps as the conversion. Do you have a leading edge factor built into this constant? (Some of the folks I know use the leading edge rather than the intended point-of-impact(POI) as the point-of-aim(POA)).

Second and carry-on example about movers, if you don't mind. I believe some folks may find this difference particularly interesting.

If we say this previous mover has a companion at 100 yards, also moving 30 mph 90 degrees how much do we need to change the lead hold to kill them both? (I was quite amazed when I first studied movers and the relationship of target distance (time-of-flight) to lead requirements. Once I figured it was angular it cleared up a lot.)

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11. ### BrentWell-Known Member

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My hat's off to the guys that can hit movers at 30 mph, that's all I can say!!

Interesting stuff!

I use Exbal to figure the lead, and usually leave it set to 1 mph so I can use multiples of that calculation if needed.

Using it to figure angled shots is one thing I find real quick and handy.

What can we do with the reticle by changing the power setting?

Concerning Exbal, its reticle optimization feature will tell you what power setting will zero the closest tick mark to the "exact" range you have entered into it... no clickin needed. OR it will simply tell you how far off the POI will be for each tick mark from the POA if using a tick mark as a POA crosshair.

Tell it you're changing the power setting to what ever setting you enter and it will show you how much closer the POI is now to POA.

This type of modifiable chart in the field is just too damn cool for the average LR hunter... like me. As S1 explains it here too, the R2 is quite an exceptional tool for many situations or styles.
http://www.perry-systems.com/palm.htm

Interesting to know these formulas and why they work the way they do but, some of that stuff is more than anyone has time to figure in the field, even if they knew the TOF for various distances etc... isn't it?

Ranging with the R2 takes a little bit of research into height and width of certain body features on animals you're hunting before hand while scouting and such but, for the most part ranging it's straight forward and simple math to do in your head in just seconds before the shot is taken. How well you learn the exact height and width of those things that need to be "bracketed" in the field is what will likely determine your accuracy in the field. I use a LRF and the R2 to acertain the sizes from a distance, as I can't always measure them on a dead animal. A young adults body size will throw you off alot let me tell you! The more data you collect, the better!

Something to consider:
Your possible amount of error in yards added to another possibly "stacked" error eminating from a reality based group size at whatever range the target is at would dictate weather the shot would be an almost certain kill.

For example, first assume two things;

1) You're always able to hold an 8" group at 800 yards consistantly.

2) The size of the body part you're bracketing for ranging purposes with the R2 is always within 10% of the size you have logged and are doing your figuring with.

You now are ready for a shot at 800 yards but this shot will be an extreme "low in a group" shot, resulting in a -4" low POI.

The body part you are bracketing is +5% larger than anticipated, resulting in a range estimation error that "stacks" another -8" low POI to the error amount, for a total possible error of -12".

Instead, a "high in a group" shot would of course cancel out some of the range error for a total error of only -4" low POI. However, considering a possible stacking effect of errors, it's wise to error on the side of caution.

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13. ### Michael EicheleWell-Known Member

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A very valid ? was brought out, can we calculate the size of deer/elk horns with this? Here were I hunt moose they have to be spike/fork, 3 or more brow tines or 50" or bigger. Now we are looking at a moose at 400 yards, the verticle hashes on the horizontal cross hair = 5" at 100 yards * 4 = 20" * 2 = 40. The moose's antlers need to fill 2.5 marks to be legal. Crosshair on far left side and then the antlers need to be half way to the 3rd mark to = 50". A similar method could be used to figure the overall length of an elks antlers. First you need the yardage, then you need to know your MOA of the marks in your scope. yardage / 100 * MOA in the reticle. We know that on the reticle in ? that side marks are 5 MOA, an elk at 400 yards that has a antler that fills 2 marks he would have a 40" long horn. 400/100=4*10MOA=40".

14. ### texasWell-Known Member

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Ok I'm middle aged and a little slow but think I under stand this a little better now.

This past weekend I was watching a combat sniper competion on tv and they had to shoot at a unknown distance greater that 500 yards to score. Most teams didn't do it. So how could we use the R2 to figure out the unknown or am I asking something that was posted and didn't see it.

S1 I know that you helped design it can it be used for farther out that 1000yds and if so how do we do it?