Making the most of Turrets and Reticle combination in long range

[flims]

In this article i would like to deal with the 'problem' that is usually encountered with many scopes on the market, that even though they can be of high quality, they always seem to trip over one feature. Mainly this is the Turret and reticle combination. What do i mean by this?

the vast majority of scopes have a Mil dot reticle which was originally designed for army purposes. I will not go into all the details of analizing a mildot reticle. if used as it is intended, it is more complex than one thinks at first glance however the mildot works in Mil radians meaning the distance from the center of each dot to the next measures 1Mil and the distance from the center of each dot to the exterior perimeter of each dot is 0.9mils.
1Mil equates 10cm at 100m or 3.45MOA at 100 yards.
1MOA = 1.047" @ 100yards. You already notice that this jumble mumble of cm and inches, meters and yards is too much confusion for the less mathematically oriented

the problem arises here. Most scopes have turrets and reticles that do not match, meaning one is in Milliradians(cm) and the turrets are in MOA (inches).
my last purchase infact was in a scope which had Milradians reticle and Mil radians turret which is the best you can get because there is no conversion to do. MOA turrets and MOA reticle are available by Nightforce and US Optics. very good scopes and I have tried both now.

If your high magnification scope has mil reticle and MOA turrets as most have you can do without the conversion if you follow this simple procedure. By this i am assuming that your reticle is in 2nd focal plain, meaning when you turn the magnification ring, the image grows but the reticle remains the same size. 90% of the scopes have reticles in 2nd focal plain and will usually be supplied this way unless requested by the purchaser. Military tend to be 1st focal plain though.

take a paper which is fairly large such as an A3 paper and place it up close, about 25yards will do for this test. im saying 25yards just to make sure any shooter is able to shoot and hit a spot on paper.
you will need to fire about 8 shots on the paper, basically KEEP aiming at the SAME POINT OF AIM.
note: If you want you can calibrate your reticle so that distance between each Dot is 2MOA. This is better for long range shooting and all you have to do more is to Dial 2MOA instead of 1 for the 8shot string.
draw a small dot and fire your first shot at it.
keep aiming at same spot and dial 1MOA right or left windage(windage knob) and always keep dialing in the same direction.
Keep aiming at the original point of aim and shoot again.
Dial 1MOA and shoot again. Do this for 8 times.
the paper you should have should look like this * * * * * * * *
when you are finished with this string of shots, dial the windage knob 8MOA back to the original place so keep track which way you were dialing.

Now keep the rifle in a steady position ideally on a rest and place the center of your crosshairs on the 4 shot. Slowly turn your magnification knob so that the image grows and at one point you will notice that the mildots on your reticle are now exactly on each of those holes that you shot.(assuming you did not screw up the shots,thats why i said keep it at relatively close range)

Once your reticle fits in the shot holes, take a little bit of tipex and draw a small line between the magnification knob and the scope tube marking the calibration of the scope. NOW you have an MOA turret and MOA calibrated reticle onthat particular magnification. This means that each 1MOA dialed on the turrets equals the distance from one Dot to the other. (now you can call them MOA dots instead of Mil dots because now they are in Inches)

Useful applications of this:
Imagine you are shooting at a 3x3inch target at 70meters. your first shot hits low by 4 MOA Dots. all you have to do now is dial 4MOA on your turret and your next shot will be dead on that target. this also applies for windage.
this way it is much easier to do any compensation and you now have a turret and reticle Matching each other. Those that have previously used my scope know how helpful this can be.
Further advantages of this is that you can now tell the other shooter next to you how much you are really dialing for wind and he can dial it into his scope assuming you are shooting same projectile at about the same velocity and at the same distance. you will see that making hits at distance is now much easier. Most guys before use to be telling the others, "listen im holding 1Mil for wind" That meant nothing because they were not using scopes calibrated on Either TRUE MIL or TRUE MOA. True Mil being 10cm at 100m or 3.6" at 100yards.

Side note, If your scope turrets have clicks in 1/4MOA per click then the distance between each shot at 25yards should be 1/4 of an inch since 1MOA is about 1inch at 100yards
. in this way you verify the exact click value of your scope.

One more tip: if you shoot at an Unknown Distance Target(UKD) and you hit really low because it was quite a way out there then what happens if you only have 4 dots below your crosshair? No problem, The vertical line of your reticle should have a total of atleast 8 Dots. use the top dot to measure the amount of drop that occured. Put the first Dot of the reticle on the POINT OF AIM and using those 8 dots on the reticle measure where the projectile hit. If it was 6 Dots down then it is 6MOA. Dial 6 MOA into the Elevation turret and you are dead on.try it out and come back with feedback

[bobbyb]

words of wisdom indeed a big help thanks

[flims]

im glad Mate! hope more will adopt the system. im planning for my S&B scope now full fletched on a nice custom!)))

[Peter v]

Very intresting text you wrote!

[sniperman]

Very smart way for calibration!

[daylite]

Good read... yeah, it's been driving me NUTS trying to find a decent scope.

The entire S&B range is 1st focal plane, and their P4Fine reticle is an incredible milRad reticle, but be sure to ask specifically for metric milRad turrets (1click = 0.1mil). However, their PMII scopes only have parallax correction above 50m, except for their brand new FT scope which is up to 70m and costs a blooming fortune, and the magnification is excessive for anything other than FT shooting. I would give my eye teeth if S&B brought out a 4-16x50 PMII P4Fine with 7m-100m parallax adjustment.

I've heard *rumour only* that the new MTC scopes 'could' be coming out with milRad turrets and a reticle on the 1st focal plane, and coupled with their excellent milRad SCB reticle (almost like the S&B P4Fine) they're going to make a killer combination.

I guess we should just keep an eye out for what they bring out next, or see if we can get a confirmation from Gary Cooper... *Gary can you confirm ???*

[classic]

I've just read your excellent piece on setting up reticles and your calculations which I intend putting to the test ASAP.

How ever on a simple note, I have two brand new 177s' a Logun MK 11 and a Falcon Lighthunter 18. The Logun is about to be kitted out with a new HAWKE Night eye Mil-dot IR. 4 - 16X50 AO and the Falcon will have a new HAWKE AIRMAX MAP 6 2 - 7 X 32 AO.

In your opinion am I right in choosing two different scopes, given that both rifles will only be used for HFT?

Best regards

[flims]

thanks for the compliment.

you could use different scopes as long as you do the same calibration for both. Your mind needs to be dealing with only one increment measurement, IE only MOA/MOA or Mil/ Mil. Stick a piece of paper on the stock then with all your data ie-
35m - 0
45m- 2MOA
60m - 5MOA
100- 16MOA etc....

[daylite]

I think the 2 key points that flims is trying to say when it comes to reticle matching is...

1. Make sure your turret measurement in clicks matches your reticle system...

i.e. mildot/SCB/P4Fine reticle with milrad turrets (1 click = 0.1 mil) (S&B 12.5-50x56 FT)
or NATO reticle with MOA turrets (1 click = 1 MOA) (Nikko Stirling 10-50x60)

This is pretty obvious, as you want to be able to measure using the reticle hold over or dial the same amount using the turrets. It makes life MUCH easier than trying to figure out the difficult calculations between MOA and milrad. 1 mil-radian = 3.4377 MOA

2. The reticle MUST be in the First Focal Plane (FFP) for variable magnification scopes.
The reason being that on a scope with variable magnification, the reticle needs to be the same size related to the target at any magnification. i.e. 1 milrad at 4X should be the same size in proportion to the target even when at 16X.
Again this is to avoid a whole pile of nasty mathematics in halving/doubling/tripling/etc that you would need to do when using a Second Focal Plane (SFP) reticle on a variable magnification scope, as the reticle would only be 'calibrated' for a specific magnification. (hence part of flims method above)
To avoid this problem on SFP scopes (like the Nikko), just make sure that when you are doing your 'measuring', that you do it at a specific magnification, then 'dial in', then reset your magnification to your shooting preference... which is a little more painful, but does work. (the crafty tipex solution of flims above)
The biggest problem with FFP scopes is that the size of the reticle at the magnification extremes... it either becomes INCREDIBLY small at low magnification, or INCREDIBLY big at high magnification (can even obscures the target sometimes)... it all depends on the magnification length and the quality of the reticle marks (S&B are masters at reticle design).


I guess the reason that we have this problem is that these new 'complex' scopes look cool through the eye piece and someone in sales and marketing thought that it would boost sales to add 'cool / complex / funky' reticles to every possible standard hunter type crosshair scopes. The problem that they have created is that they have not matched their turret systems to their reticles, nor have they put their reticles on the First Focal Plane.

It's a case of 'Fashion' meets shooting...

[alfidog]

What do you boys think of this as a long range scope:

http://www.border-barrels.com/

3-18 x 42 with cm clicks first focal plain and a good reticle.

I have the 2.5- 10 but no parallax adjustment, great glass though.

[JoKerr]

Most scopes have turrets and reticles that do not match, meaning one is in Milliradians(cm) and the turrets are in MOA (inches).

Correct in that most mildot scopes have MOA turrets.
However, miliradians (as used by the military and not mathematicians) are not metric or in cm and MOA are not in inches.

They are both a measure of angle.

The mil (360 degrees = 2pi radians for mathematicians, ie approx 6283 miliradians, but the mil was changed for ease of use around 100years ago to 6400mil for artillery) is an angle that will subtend a length of 1 for a distance of 1000. Therefore at 100m the drop (or whatever we're measuring) will by 100m/1000, which is indeed 10cm (or one tenth of a metre).
Similarly, at 100yds 1mil will equate to 1/10 of a yard (or approximately 3.6")
i.e. 1mil = 1yd at 1000yds or 1mil = 1m at 1000m.

1MOA = 1.047" @ 100yards. You already notice that this jumble mumble of cm and inches, meters and yards is too much confusion for the less mathematically oriented

One MOA (minute of angle) is 1/60 of a degree. It is indeed 1.047" at 100yds, but you can forget the .047" and equate it to 1" at 100yds as .047" is 1.2mm. Now I like perfection better then most but 1.2mm at 100yds, I'll live with it.
At 1000yds the difference is a whopping 12mm. If you really need that extra 12mm then I salute you.

the mildot works in Mil radians meaning the distance from the centre of each dot to the next measures 1Mil and the distance from the centre of each dot to the exterior perimeter of each dot is 0.9mils

This will depend upon your scope but every mildot scope I've used has either dots of 0.2 mil in length and usually half that in width (ie 0.1mil) or 0.2mil round dots, favoured by the US military and Leupold now, whereas the USMC and many scope manufacturers use the 0.25mil by 0.125mil oval dot. Either type of dot is indeed 1mil centre to centre but the distance between dots 0.8mil (0.2dots) or .75mil (.25 dots) which is a much more useful measure than centre of one dot to the edge of the next - 0.9mil for .2mil dots and .875mil for .25mil dots.

OK the difference is small but then the whole premise was to find something that better when compared to the mil/MOA method. The more small errors in the system (or the explanation) then the less likely one is better than the other.


Remember: ONE Mil is approx 3.5MOA. If you remember that then you can't go far wrong.

JK

ETA found this explanation of the reticules. http://www.imtt.net/downloads/mildots.pdf

[guff878]

Great way of calibrating your scope, especially for us who are not maths experts. I will defiantly give this a go when I finally, if ever, get a chance to shoot again.

[18 Wheeler]

What do you boys think of this as a long range scope:

http://www.border-barrels.com/

3-18 x 42 with cm clicks first focal plain and a good reticle.

I have the 2.5- 10 but no parallax adjustment, great glass though.

For me 1cm increments (@100M) are not a fine enough adjustment for air rifle use.

Nice scopes but not well suited to we airgunners in my view.