Frank,
This is pretty comprehensive and shows how much you thought about how to present the subject in a cohesive and comprehensive manner. I took your request at face value and went through the whole document with an editing mindset. This means that I didn’t add much content, like you asked, but I used the editor's pen and fixed a few small errors.
I know this is not addition of content, as I’ll leave that to those better than me, but it was done with all respect and good intent. Use some, all or none of it. Your call. I do realize that some, if not all the corrections I made are likely needed due to the ill will bestowed upon all online writers by the nefarious intentions of those damned autocorrect minions. I
italicized things I felt needed to be replaced,
wrote in cyan things I thought needed to be added or to replace something, and put my comments in
(parentheses).
Thanks for taking this in in a comprehensive manner.
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lowlight, post: 8495538, member: 7
“where I am so far, I still need to clean it up, add in some graphics to push the point
But check my work, I am blind to this right now because my brain is bored with it, so I am probably missing the obvious. My brain just hates the direction this topic has gone,
Check my work give me some missing points or expand on points I made, I want as complete a picture as possible so that means more eyes and more voices.
We need it easy to follow, harder to debate, hopefully, this answers the question better when all finished
-------------------------------------------------> Start here:
Milliradians TMOA & SMOA/IPHY
Milliradian's - Mils - MRAD - Mils are an angle, the angle part is very important to consider because while all angles have a linear equivalent we do not need the linear values to successfully use Mils.
However, while we do not need the linear values to shoot well with Mils, is is helpful to know them in order to understand the relative relationships for each system. (Here I thought that there needed to be a transition from telling the reader that linear measurements are not needed to jumping into a lot of the linear measurements and linear equivalents.)
- An Angle which subtends an arc whose length is 1/1000th of the distance from the vertex.
- 1 yard @ 1000 yards
- 10 centimeter @ 100 meters
- 3.6 Inches @ 3600 inches or 100 yards
Most scopes adjust in .1 Mils or 1/10th, which equals .36” per click @ 100 yards. There are scopes that also adjust in .05 Mils .18” @100 yards for finer adjustments. In this case, you can think of money, 10 pennies equal 1 dime or each click is a penny
, (comma) every full milliradian is a dime.
Milliradians are base 10 but since they are
angle angular/angles, are not necessarily metric, but were added to the metric system in the early 1950s. Angles work with any unit of linear measurement.
Pros:
Base 10 units are easier to work with over fractions
Wind based formulas are easier to use with Mils
Smaller numbers to remember -
= Less movement for the same elevation
Widely used around the globe
Better Reticle Choices
Cons:
Highly misunderstood in America
Needs to be converted using 3.43 when talking MOA
Actual offset between 1/4 MOA is negligible = .0235MOA
Minute of Angle - MOA - True MOA - TMOA
MOA is an angle just like Milliradians, this angle can have a linear equivalent like any other, so when discussing TMOA we want to reference the angles not the inches found between them.
Minute of Angle - is a unit of angular measurement equal to 1/60th of 1 degree.
TMOA = 1.047” at 100 yards.
Pros:
Different scope adjustment choices: 1/8th, 1/4” 1/2” & 1”
(Isn’t this going to confuse some by using “ here instead of just MOA?)
Used in the US for many years
NRA Paper targets are calibered in MOA
Cons:
Misused by many shooters over the years
Manufacturers mix TMOA with SMOA
Fractions - you hated them in school for a reason
Limited Reticle Choices
No Standard among Manufacturers - you don’t always have a 1 MOA reference.
Bigger numbers to remember.
Shooter MOA or Inches Per Hundred Yards
SMOA or IPHY is a modified version of TMOA that rounds the linear value of 1.047” to 1” at 100 yards. This was a
bit big mistake made years ago by people shooting mid range distances. This creates a built in 5% error when mixed with TMOA.
Many errors in setting up ballistic calculators come from mixing SMOA Scopes with TMOA values in the computer. The 5% error factor grows at distance and the farther you shoot the bigger the error.
Many of the
uniformed with uninformed will state it’s a 1/2” different at 1000 yards because 1 MOA equals
10.47” . However we do not use 1 MOA to reach 1000 yards we have to combine the adjustments to over 30MOA in most cases. That means the 5% error is
multiple by multiplied 3x if not more depending on the system. At 1000 yards this can mean as much as 20” of difference.
Shooter MOA has to be paired with like values. The turrets and the reticle must match and often they are mixed between TMOA and SMOA.
Pros:
Commonly found in lower cost scopes
Easier ranging formula than TMOA
Cons:
5% error when compared to TMOA
Misunderstood as equal to TMOA
Customer Service will tell you, Yes you have MOA without specifying which one
fo of the two.
If ever shooting with others, causes even more confusion.
The Practical Side of the Discussion
All three systems work when used properly. For individuals shooting on their own as part of their hobby, the system of adjustment is a minor consideration. However when branching out to other areas of sport such as competitions, communication because the bigger factor. Most Tactical Shooters communicate in Mils so MOA shooters have a conversion to consider. In F Class and BenchRest more shooters use MOA. The targets are calibrated in MOA and communication on the line will be easier speaking the same language.
On paper one may appear “finer” then the other, however broken down when actually used the difference is roughly .0235” between the two. You have less than a bullet width of difference, the likes of which cannot be held by most shooters.
Taken from a mathematical standpoint,
Example: You impact 1.346 MOA right of your POA
1/4 MOA Gets us: 1.346 - 1.250 (5 clicks) = .096 MOA away from POA
.1 MRAD or .344 MOA Gets us: 1.346 - 1.376 (4 clicks) = -.030 MOA away from POA (negative just means we are left of the POA now, but still closer to POA then the 1/4 MOA)
View attachment 7307537
The first graph has POI on the X axis (.002, .004, .006 .. 3 MOA) and the Y axis is how close you can get to the POA, two plots, one for 1/4 MOA and one for .1 MRAD. As we can see (just like the example above) sometimes MRAD is closer to POA then MOA, although not as often. As I calculated it, 1/4 MOA gets you closer ~63% of the time and . 1 MRAD gets you closer ~36% of the time with about a 1% tie.
The second graph plots the difference between how close 1/4 MOA is vs how close .1 MRAD is for each POI of .002, .004, .006 ... 3.0 MOA.
The beginning of the graph where it is flat is because from 0 to .125, neither 1/4 MOA nor .1 MRAD can get any closer then each-other. The parts in this graph above the X axis represent when 1/4 MOA is further from the POA then .1 MRAD. And the parts in this graph below the X axis represent when 1/4 MOA is closer to the POA then .1 MRAD.
The takeaway from the Finer Adjustment debate is: but which one is actually closer to center, the fact one number is different from the other only means you are missing a major component of the debate which cannot be determined correctly on paper. We are assume ballistic solutions are to center, rarely are they off enough to miss if properly trued.
But I “think” in Inches:
This argument is one of ignorance, we don’t want to think we want to read and communicate in a language that common across the platform we are engaged in. So this is the first major consideration, we are not thinking about the adjustment we are reading it.
Milliradian’s work with inches, yards, and miles the same as MOA. There is
no difference in the results just in the communication between the shooter and his system. Many will reference the finer discussion, but mils can subtend very fine also.
.3 Mils = 1.08” at 100 yards, so you can move that same value as you are moving .36 per .1 adjustment.
Here is an example of how both work and can be interchanged using simple math.
875-yard target or 800m:
Mils = 6.3
TMOA = 21.6
SMOA = 22.6
All three of these will hit the same target under the same conditions. Mils and TMOA can be converted from one to the other using 3.43 as a multiplier or constant.
6.3Mils x 3.43 = 21.6 MOA
Ranging Formulas In Yards:
Another area of variation is ranging between TMOA and SMOA
The 5% error has to be considered.
Mils
Range in Yards = Target size Inches x 27.7 / Mils Observed
TMOA
Range in Yards = Target size Inches x 95.5 / TMOA Observed
IPHY / SMOA
Range in Yards = Target size Inches x 100 / SMOA Observed
The work is the same the issue is usually the reticle. Most MOA based scopes use 2 MOA reticle sub tensions, some do have 1 MOA choices however Mil based reticles have a finer sub tension being .1 ranging trees or .2 Sub-tensions.
.1 Mil = .36”
.2 Mils = .72”
1 MOA Reticles = 1 MOA
2 MOA Reticles = 2 MOA
So using the reticle you have a finer area of adjustment vs the MOA versions currently offered.
Shooter Mindset
We are no longer thinking in inches because in the first place you are estimating the number of inches away from the target. We have a calibrated ruler 3 inches in front of our nose. When the reticle matches the adjustments
that of most scope
s automatically today, what you see is what you get. The angles work for you and not against you.
Start looking at the reticle like a ruler and measuring based off the unit of adjustment vs looking and trying to estimate the distance.
In the past, this was taught by compounding the linear value with MOA. They wanted you to use the linear value and multiply by the range. This is meaningless in shooting but instead makes you want to multiply.
I 8” Consider a miss 18” away from a target at 875 yards, so 1 MOA at 800 is X 8, so I need 1 MOA but now I have to figure in the extra 75 yards to calculate a value.
Instead, just read it in the reticle and say,
I need 1.25
” MOA adjustment change to hit the center of the target or for a Mil shooter reading .2 Mils off, just dial .2 Mils.
The more you shoot and use the reticle the easier it will be too overlay the adjustment value to the target. I see misses in
the Mils
, not inches.
The Wind
Using Mils
is makes it easier to learn wind reading as well. The only real MOA formulas are based on a specific bullet. There are constants and values that have to be translated to your equipment. The USMC Wind formula most use is based off a 168gr going 2550fps, so those constants are not accurate for most people. In order to translate the constants to the bullet being used you need the correct value to work the formulas in reverse. If you have the correct value, the formula is not needed.
The British Method is again using a specific bullet.
We can use Mils to determine your MPH Gun which then accurately lines up the holds based on the range.
6 MPH Gun @ 6 MPH Full Wind value
200 - .2
300 - .3
400 - .4
500 - .5
600 - .6
6 MPH Gun @ 12 MPH Full Wind Value
200 - .4
300 - .6
400 - .8
500 - 1.0
600 - 1.2
This is very easy and accurate, something that works with any bullet combination.
MOA Wind - British Method
10 MPH wind is your base wind.
1 MOA @ every 100 yards
Wind MPH 2-3 MPH = light, 5MPH = medium
10MPH = base, 20MPH = heavy
Example:
Range 600, velocity 10mph = 6 MOA
Range 600, velocity 5 mph = 3 MOA
Range 600, velocity 2-3mph=1.5 MOA
Range 600, velocity 20 mph = 12 MOA
This will work with limited success because it is based on a specific bullet.
You can convert the MPH Gun to MOA but it is much more complex. Simplicity is the real winner when it comes to shooting.
Using Clicks
Clicks are not a good way to communicate. It goes against the principles of speed and simplicity. It’s better to speak in the correct language vs Shorthand in this case because it’s really longhand cursive.
Dial on 20.6 MOA vs 82 clicks, this immediately gets the brain overthinking.
6.3 Mils = 63 clicks, what is easier counting 63 pennies or 63 cents in dimes?
Use the whole number first, then fine-tune it,
Dial to 20, then add in .6 MOA which is 3 clicks.
Dial to 6 then add in .3 Mils which is 3 clicks
One On a firing line with different shooters, who can potentially be using different click values, you have to know that click value to give the appropriate number. If you are using 1/2 MOA adjustments that value is different from a 1/4 MOA adjustment in terms of clicks.
The only time you see clicks work is adding one or two more. “Come up a click” that adjustment is so small it’s easiest to address in this fashion. However, a 5 MOA change referenced via clicks is coming off wrong.
Speaking in clicks beyond one or two should be dismissed as bad practices.
