Advanced Marksmanship Ranging w/ Reticle; any techniques to improve

[Alan Griffith]

Today, at our Utah tactical shoot, we had 4 unk distance steel gongs; 18" round or square. Some shooters lased them, I used my NF NP-R1 reticle @ 22x and my USO FFP spotter. I hit 3 of 4.

I'm doing this from memory, so forgive if i'm off.

The missed target was the longest @ 824 yds. My calc put it at 859.5 yds. I kept coming up with 4.5 minutes.

18"/2 min x 95.5 = 859.5 yds. A 35 yd difference. Had I used 2.1 min I'd have calc 818 yds and should have hit it.

Another I recall was 18"/4.5 min x95.5= 382 yds yet it was 364; I think! Means I was off by 18 yds even though I hit it.

I notice that at distant targets, if off even .1 min it's fairly substantial; enough to miss!

What, if any, tricks are their to assist one in ranging more accurately with a reticle?

I realize a larger target helps.

Alan

 

[Lindy]

Re: Ranging w/ Reticle; any techniques to improve

I use a mil reticle, so keep that in mind.

An essential skill to master is to be able to break the reticle down finer than 0.1 mil increments.

One way to practice that is to set up a target at a distance where the image size of the target is precisely the resolution you want to practice.

Use the mil relation formula - or a Mildot Master - to calculate the distance you want.

<div class="ubbcode-block"><div class="ubbcode-header">Code:</div><div class="ubbcode-body ubbcode-pre" ><pre>
target size (inches) * 27.77
distance = -----------------------------
image size in mil
</pre></div></div>

For example, if you want a 12 inch target to measure 1.65 mils, then:

distance = 12 * 27.77 / 1.65 = 202 yards

At 196 yards, that target will measure 1.7 mils.

At 208 yards, that target will measure 1.6 mils.

By moving back and forth between those distances, you can practice reading the reticle to 0.05 mils, and doing that will greatly enhance your accuracy at long distances.

 

[coldboremiracle]

Re: Ranging w/ Reticle; any techniques to improve

Good info Lindy, thanks.

 

[Crazy Dog ll]

Re: Ranging w/ Reticle; any techniques to improve

.

 

[Alan Griffith]

Re: Ranging w/ Reticle; any techniques to improve

Lindy,

Wow! That blows my mind that I need to get down to something finer than .1 MOA but you're the man, so I will start working on it.

Thanks,

Alan

 

[Lindy]

Re: Ranging w/ Reticle; any techniques to improve

You probably don't need to get finer than 0.1 MOA.

I use a mil reticle. A resolution of 0.05 milliradians is equal to 0.05 * 3.438 MOA, or 0.17 MOA. I'd round that off to 0.2 MOA.

However, the same technique works for refining your ability to measure using a MOA reticle.

 

[TiroFijo]

Re: Ranging w/ Reticle; any techniques to improve

You have to know your limitations... your target is a bit too small for accurate range estimation with a reticle.

An 18" target subtends 2.0 MOA at 859.5 yds.

If you read 2.1 MOA, that is a -5% error in range, 818.5 yds. That is a big miss with a 308 on a target or that size. Even if you have superhuman eyes an miss by just 0.05 MOA (read 2.05), that is a -2.5% error, 838.5 yds, and still (barely) a miss with a 308.

I don't think that anybody can read better than 0.05 mil (0.17 MOA) with reliability, and 0.1 mil (0.34 MOA) would probably be a more realistic number due to illumination factors, how square (horizontally and vertically) are you to the target, etc., and this for KNOWN size targets, it gets much worse with real world targets that vary in size.

 

[Chilo]

Re: Ranging w/ Reticle; any techniques to improve

tag

 

[dontstrokeme]

Re: Ranging w/ Reticle; any techniques to improve

.

 

[Guest]

Re: Ranging w/ Reticle; any techniques to improve

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: GSSP</div><div class="ubbcode-body"> What, if any, tricks are their to assist one in ranging more accurately with a reticle?
I realize a larger target helps.</div></div>

Retical subtention reading, is a perishable skill. On a good day I can read to 1/4 IPHY,...once that skill is mastered the next trick, is knowing how to read the target color that adds or subtracts the subtention in different lighting. I'm still working on that all the time. Yellow, White, and bright orange are my worst. Any target thats dull is much easier, and a camo'd one(once found)is the easest of all.

I've a 17X on a .308 and past 700yds yds the error range to miss a target is very small if one does not factor everything. This is why I try to only work the (retical only).308 on UKD to about 700yds, past that I move up to 300wm an 22X.

 

[Mo_Zam_Beek]

Re: Ranging w/ Reticle; any techniques to improve

Over the last few years I have never been off more than 3% of my MIL call vs an LRF. That all said 3% can mean something at a distance. Someone said - know your limitations. I think that can be expanded to the limitations of the system. You may be a super stud and be able to range under ideal conditions with great accuracy, however add a little mirage and a long range and you will wish you had lased it.

I think MIL'ing is a good skill to practice but I also think it should be confirmed with an LRF if there is anything other than bragging rights.

FWIW - a practice thought: OR Shooter and I play a game wherein you get a GPS waypoint and a bearing some funky place in the woods. Some where in the distance is a target off that bearing. You must find it, range it with your rifle scope only, and make the hit. Sliding point scale based on accuracy and anything other than a 1st round hit.

Good luck

 

[TiroFijo]

Re: Ranging w/ Reticle; any techniques to improve

It all depends on how flat your load shoots, and the size of the target. With a 308 M118 LR or clone load (175 SMK at about 2680 fps), std. cond.:

With a torso sized (18"x28") target:

At 650 yds the maximun range estimation error can be +/- 23 yds, or a 3.5% error. IF you can consistently read with +/-0.05 mil accuracy, the object you read to estimate distance has to be 1.4 mils or larger. This subtends about 32.8" at this distance, so if you are reading a smaller object your chances are not very good.

With a head sized (6"x8") target:

At 425 yds the maximun range estimation error can be +/- 25 yds, or a 5.9% error. IF you can consistently read with +/-0.05 mil accuracy, the object you read to estimate distance has to be 0.85 mils or larger. This subtends about 13" at this distance, so if you are reading a smaller object your chances are not very good.

 

[kmussack]

Re: Ranging w/ Reticle; any techniques to improve

AKA, Danger Space

 

[TiroFijo]

Re: Ranging w/ Reticle; any techniques to improve

Danger space <span style="font-style: italic">combined</span> with accuracy of mil reading, and how the range estimation accuracy is related to the known object size

It also helps to have a good reticle (TMR, Gen II, etc.), and high magnification (16X or more). But of course you can only use high magnification if mirage allows.

 

[rkgsmith]

Re: Ranging w/ Reticle; any techniques to improve

I ran into an issue last year practicing for a comp. We had set up a course of steel targets on a known distance range. The farthest target was 600 yards and the target was about as big as a larue. I knew the range, and knew what the mil reading should have been using the Leupy TMR spotter, but just couldn't see what I needed to see. Target was painted white on a very sunny, but cool day in April. Since then I have tried to really factor in the wheather conditions as much as the target. I tend to back ever so slightly on my mil call when the target is shinning in the sun. This seems on average to get me closer on the long calls.

 

[JRWALLSIII]

Re: Ranging w/ Reticle; any techniques to improve

One BIG help is having a great recticle.

IMO that is SB P4 Fine. It is broken down into .2 mill with stadia lines, center between the lines .1 mill. I think leupold TMR is the same way.

Also just because you spend a couple thousand on a optic don't take for granted the recticle is correct. I found this out the hard way last year at train up for ASC. My high end optic was .1 mill off on readings. Made me absolutly sick. Would have never known had it not been for Verns train up. Everyone was getting something a little diffrent than myself. Got behind some of the other guys scopes and spotters and came up with the same readings they did. This was also confirmed by other shooters as well.

Check your equipment!!! Listen to Lindy always!!

 

[CouncilOfDave]

Re: Ranging w/ Reticle; any techniques to improve

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: .257</div><div class="ubbcode-body">One BIG help is having a great recticle.

IMO that is SB P4 Fine. It is broken down into .2 mill with stadia lines, center between the lines .1 mill. I think leupold TMR is the same way.

Also just because you spend a couple thousand on a optic don't take for granted the recticle is correct. I found this out the hard way last year at train up for ASC. My high end optic was .1 mill off on readings. Made me absolutly sick. Would have never known had it not been for Verns train up. Everyone was getting something a little diffrent than myself. Got behind some of the other guys scopes and spotters and came up with the same readings they did. This was also confirmed by other shooters as well.

Check your equipment!!! Listen to Lindy always!! </div></div>

I can't imagine anything more frustrating than having problems because of faulty equipment, while thinking that it was me making the error.