• Watch Out for Scammers!

    We've now added a color code for all accounts. Orange accounts are new members, Blue are full members, and Green are Supporters. If you get a message about a sale from an orange account, make sure you pay attention before sending any money!

Rifle Scopes Why Mils over IPHY?

Re: Why Mils over IPHY?

Troublemaker!
laugh.gif


Yes, you have created an angular measurement when you equate a specific linear measurement of width at a specific linear measurement of distance.
 
Re: Why Mils over IPHY?

OK, so if I have this straight you have chosen to invent a new angular measurement system you have labeled as IPHY. Am I starting to get it?
 
Re: Why Mils over IPHY?

Yes sir, though I certainly did not invent it.
I would argue that all measurement systems were invented, and then someone else reinvented them, and again.
Lindy can probably list more angular measurement systems than we want to hear.
laugh.gif


I would be surprised if IPHY was not alot older than any of us.
 
Re: Why Mils over IPHY?

IPHY used to be called by some "Shooter's Minute of Angle", which is such an inaccurate bastardized term that IPHY is greatly preferable. I don't know who started calling it IPHY - but I'm grateful to whoever it was.

 
Re: Why Mils over IPHY?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rafael</div><div class="ubbcode-body">Yes sir, though I certainly did not invent it.
I would argue that all measurement systems were invented, and then someone else reinvented them, and again.
Lindy can probably list more angular measurement systems than we want to hear.
laugh.gif


I would be surprised if IPHY was not alot older than any of us. </div></div>

No more troublemaking from me, well, for now anyway
wink.gif
...

Actually, I don’t remember much from high school, hell sometimes I don’t remember what I had for lunch, but in General and Shop Math there wasn’t a lot of this going on.

I must have completed Geometry too, just to graduate HS, but I honestly don’t remember Archimedes getting all wadded up over his angular units
grin.gif
.

There might just be room for both opinions here though.

It would appear NineHotel has a point that IPHY (so I guess CMPHM is in jeapardy as well?
frown.gif
) is not one of the commonly accepted units of plane angular measure in the world of math and science, at least I can't find it specifically. But I do recall that “Shooter’s Minute” has been around for a long time, I just took it to be a crutch for those disinclined to do the 1.0472 moa math, at least that’s the way Archimedes explained it
wink.gif


There are only two accepted units in the geek world that apply to our field, and they are by far the most common; the radian (rad) and divisions thereof such as milliradian (mrad) and the degree and divisions thereof such as minute of angle or arc/arcminute (moa), well...unless we want to get into grads...Naaa, never mind
crazy.gif


BUT...

Lindy has even more room here than just the “Shooter’s Minute”. By definition, a plane angle consists of straight lines that incline toward each other and meet at an apex and are defined as the ratio of lengths. Well, IPHY sounds suspiciously like a ratio to me...And so then does CMPHM
grin.gif


Ok, now on to “metric scopes”
wink.gif
smile.gif
grin.gif


Sorry Raf...Couldn't resist
cool.gif


 
Re: Why Mils over IPHY?

....and for that reason I started using the term IPHY.
I don't recall who first coined it here. Maybe me, maybe Doc, maybe someone else. I do recall conversations with Doc where both of us despised the terms SMOA and TMOA.
MOA shouldn't need to be clarified "True" and anything that isn't MOA......isn't.
 
Re: Why Mils over IPHY?

Bob, I contacted someone smarter than me. He says yes, you can call IPHY (as a label/name only) an angular system that defines the following:

"IPHY could be defined without using any linear units, IE, 1/22620 of a circle".

That makes it much more clear to me. Why rely on something like MIL or MOA when you can rely on the simpler 1/22620 of a circle?
 
Re: Why Mils over IPHY?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: NineHotel</div><div class="ubbcode-body">Bob, I contacted someone smarter than me. He says yes, you can call IPHY (as a label/name only) an angular system that defines the following:

"IPHY could be defined without using any linear units, IE, 1/22620 of a circle".

That makes it much more clear to me. Why rely on something like MIL or MOA when you can rely on the simpler 1/22620 of a circle? </div></div>

LOL
That's funny as hell, Leo!
laugh.gif

I am glad I did not have a mouthful of beverage in my mouth when I read that.

Who was this smarter person....and how do I contact them to learn more?

Would you mind if we borrow from you/them and officially change the name from IPHY to 1/22620th?

Perspective can be quite humorous.
laugh.gif
 
Re: Why Mils over IPHY?

Bob - note that those definitions of angle are shown independent of unit type, therefore bolstering my point that angular systems are linear measurement system independent.

And sub2, if you research both the metric system and the mil-radian system you will see that the were invented hundreds of years apart and one is not based on the other. It is an odd and very convenient coincidence that mil-radian and the metric system 1 cm/100M line up out to 8 places to the right of the decimal point, but they are not based on each other.
 
Re: Why Mils over IPHY?

Good points. No argument there, Leo.
My point is that these are all inventions of men, or likely "a" man for each of them. No more or less significant than any other arbritrary system one chooses to use. For that matter, why not use a system designed around the linear units of measure I am more familiar with, since that is part of the goal anyway?
I can also see the point that Mils are in common use in this community, but I don't see it as an absolute.

Since you went down that dark alley....
laugh.gif

Which is more rediculous?
IPHY at 1/22620 of a circle?
MOA at 1/21600 of a circle?
or
Mils at 1/6283 of a circle?

They all seem rediculous when you look at them that way.
laugh.gif

I believe MOA is the only one that describes a full circle in whole numbers.
But then.....we don't really need a full circle since no earthly trajectory requires 21600 MOA of adjustment.
 
Re: Why Mils over IPHY?

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">It is an odd and very convenient coincidence that mil-radian and the metric system 1 cm/100M line up out to 8 places to the right of the decimal point, but they are not based on each other.</div></div>

Umm, sorry, incorrect.

A radian is a unit based upon the recognition that there are 2 times Pi radians in a circle. That's a physical fact not invented by man - it's just a physical reality.

A milliradian is simply one thousandths of a radian, and is an angle such that the length of an arc subtended by that angle is one-thousands of the distance from the vertex of that angle to the arc.

So, the length of the arc subtended by an angle of one milliradian at a distance of 100 meters is <span style="font-weight: bold">exactly</span> - not approximately - one-thousandths of 100 meters. Which happens to be a tenth of a meter, more commonly known as 10 centimeters.

Most scopes which adjust in fractional milliradians adjust in tenth milliradian increments, corresponding to an increment of one centimeter at 100 meters.

You're right that the length of that arc at one-thousands of the distance is not unique to the metric system - because it's exactly the same for <span style="font-weight: bold">every</span> unit of linear measure. (In deference to others, we won't get into attoparsecs.)
laugh.gif


Now, that's the length of the arc - which means the linear distance across the ends of that arc is a bit less than the length of the arc. But that's a difference which for shooting purposes makes no difference.
 
Re: Why Mils over IPHY?

If you want your head to really hurt, calculate how much shorter the linear distance across the arc subtended by one milliradian is, expressed as a percentage of the true arc length. You may wish to know that many scientific calculators are not sufficiently precise to calculate that. Show your work.
laugh.gif


My wine glass is empty. I'm off to refill it.

 
Re: Why Mils over IPHY?

Honestly, why doesn't someone make a scope that adjusts in grad so we can have something else to argue about?



Here ya go Lindy:

sin(.001)=y=.0009999998333...
cos(.001)=x=.9999995000004...
x_1=1, y_1=0 (unit circle)
sqrt((x-x_1)^2+(y-y_1)^2)=0.00099999995833333385416666356646826...

^that/.001 = 99.9999958...%

 
Re: Why Mils over IPHY?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: NineHotel</div><div class="ubbcode-body">And sub2, if you research both the metric system and the mil-radian system you will see that the were invented hundreds of years apart and one is not based on the other. It is an odd and very convenient coincidence that mil-radian and the metric system 1 cm/100M line up out to 8 places to the right of the decimal point, but they are not based on each other. </div></div>

Ya'll were busy during dinner...

Uhmmm, just wondering where I gave the impression I was under the delusion that the "metric system" was based upon the "mil-radian system" or visa versa? I sure can't imagine putting anything like that in my previous posts, even with the kidding around.

Since you brought it up though, actually I have looked into the "metric system" and SI a bit, starting years ago as a result of needing to use aspects of it for work, and I continue to maintain an interest in it for the same reason. Long before I had to enter the "metric"/SI world periodically, I looked into the "mil-radian system" a bit too, in fact, quite a while ago thank you
frown.gif
and I still find it of interest to this day like most here.
wink.gif


BTW, you might wish to do a little research and revise your chronology re: "the(y) were invented hundreds of years apart".
wink.gif
 
Re: Why Mils over IPHY?

I used my IPHY scope yesterday to do the ranging stage at the NorCal match.
This was the first time I have ranged in the field, laying on gravel and stickly things, under the clock and with the pressure of competition.
I finished all targets on time and got 6/10 within 10yds (IIRC the best score was 7/10 out of 54 shooters). The others that I missed were close enough to have been hits if I used my range estimation and fired. I think IPHY is the easiest for ranging.
For dialing what you see, I don't see any difference. Any reticle that has matching turrets is a "watch the splash and dial correction" proposal. Period.
Its funny that folks can't see 1/4 IPHY at 1K, but I heard a lot of talk about .1mil corrections at the 1K range yesterday.....

All that said, I'm switching to mil/mil because:
a)everyone I shoot with regularly has mil setups
b) I don't need to range with my reticle often and the real kicker-
c)<span style="text-decoration: underline">Premier ain't making Heritages in IPHY!!!!!!</span>
 
Re: Why Mils over IPHY?

Well, here's a relatively easy method.

A line between two points on a circle is called a chord.

Use the following symbols:

S = arc length
R = radius of the arc
a = chord length
theta = angle in radians

S = R * theta
a = 2 * R * sin(1/2 * theta)

So, the ratio of the chord length to arc length is simply:

2 * sin(1/2 * theta) / theta

Multiply that by 100 to get the percentage.

Without getting tedious about the precise value of the sin of 0.0005 radians, we'll just use 4.999999791666669e-4, and two times that is 9.999999583333338e-4.

Divide that by theta = 0.001 radian, and you get:

0.9999999583333338

Multiplying by 100, we get:

99.99999583333337 percent

So, that's the percentage that the linear distance is of the arc length across the ends of a one milliradian arc.

Which is why I said that for shooting purposes, the difference doesn't matter.

And my wine glass is empty, again. Damn, this is fun!
 
Re: Why Mils over IPHY?

And that my friends, is why Lindy rules the mil vs moa threads!

Frank is no nonsense spot-on common sense from untold hours playing with rifles and riflemen in the field actually
applying what gets debated in cyberspace ad nauseum, and Lindy nails the head splitting math with ease.

I'm designing my "mils aren't metric" tattoo shortly........
 
Re: Why Mils over IPHY?

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Your answer in not too far off - but the method is not correct. Anyone else?</div></div>

My answer isn't off at all, nor is the method incorrect. If you continue on with my method you'll find it's the proof for yours.
 
Re: Why Mils over IPHY?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sub2.908cm/100m</div><div class="ubbcode-body">

BTW, you might wish to do a little research and revise your chronology re: "the(y) were invented hundreds of years apart".
wink.gif
</div></div>

203 years apart to be exact. That's "hundreds" by my definition - yours?
 
Re: Why Mils over IPHY?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lindy</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">It is an odd and very convenient coincidence that mil-radian and the metric system 1 cm/100M line up out to 8 places to the right of the decimal point, but they are not based on each other.</div></div>

Umm, sorry, incorrect.

A radian is a unit based upon the recognition that there are 2 times Pi radians in a circle. That's a physical fact not invented by man - it's just a physical reality.

A milliradian is simply one thousandths of a radian, and is an angle such that the length of an arc subtended by that angle is one-thousands of the distance from the vertex of that angle to the arc.

So, the length of the arc subtended by an angle of one milliradian at a distance of 100 meters is <span style="font-weight: bold">exactly</span> - not approximately - one-thousandths of 100 meters. Which happens to be a tenth of a meter, more commonly known as 10 centimeters.

Most scopes which adjust in fractional milliradians adjust in tenth milliradian increments, corresponding to an increment of one centimeter at 100 meters.
</div></div>

About terminology;
Lindy is right, as usually.
smile.gif

Radian is universial unit. According to SI -system, abbreviation is Rad.

Some fine tuning: In same SI -system, prefix "milli" is always 1/1000th. Only right abbreviation for it is "m" ,small m. "mm" is "millimeter", 1/1000th of one meter. Capitol "M" would mean "Mega", which is original unit times 1 000 000. Like in computer world, Mb, megabyte, or 1 000 000 bytes.

Summa summarum;
When talking about 6283 "metric mil" (though its not really metric), only right abbrevation is "mrad".
"mil" is universial slang word, which can mean circle divided by 6000 (comblock mil), 6283 ("metric" true mil) or 6400 (western mil).

I dont know why "mrad" or "mil" is commonly perceived as metric system.
Likely because prefixes and abbrevations come directly from SI -sytem -which defines all metric units.
 
Re: Why Mils over IPHY?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rafael</div><div class="ubbcode-body">But then.....we don't really need a full circle since no earthly trajectory requires 21600 MOA of adjustment. </div></div>

I can think of at least one situation that requires 21600 MOA. The same that requires 360 degrees.


21600 MOA is the same as 360 degrees is the same as 0 degrees is the same as 0 MOA
laugh.gif
 
Re: Why Mils over IPHY?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JL</div><div class="ubbcode-body">
I dont know why "mrad" or "mil" is commonly perceived as metric system.
Likely because prefixes and abbrevations come directly from SI -sytem -which defines all metric units.
</div></div>

I think it is two fold. First, you are correct the the term "milli" is associated with the metric system. I also think it has to do with who used the system for ranging. The military was the first common users, they used meters to describe a distance. Also, the definition of milliradian is also often given with metric terms i.e. 1 centimeter at 1000 meters.
 
Re: Why Mils over IPHY?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: gugubica</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rafael</div><div class="ubbcode-body">But then.....we don't really need a full circle since no earthly trajectory requires 21600 MOA of adjustment. </div></div>

I can think of at least one situation that requires 21600 MOA. The same that requires 360 degrees.


21600 MOA is the same as 360 degrees is the same as 0 degrees is the same as 0 MOA
laugh.gif
</div></div>
I deserved that!
laugh.gif
 
Re: Why Mils over IPHY?

My deal is this. Mentally I range in inches. Meaning, looking through the reticle and sizing the target via the reticle my mind says that if it's a 20" piece that I'm looking at and I see 4 moa in my scope I know it's at 500 yds. 20/4=5 + two 0's. I don't even have to look at a mil-dot master or any sliderule even. Granted that is simplifying the MOA/IPHY system. I don't differentiate the two as they are so close. So close in fact that an accuracy level of a tactical shooter will never matter.

In mils the formula is 20 x 27.778 = 555.56 x .9mil =500.

What I'm not getting here is how you just 'read' mil's then dial in the answer. You've got to have a table or something to convert the linear measurement you see within the angular measurement you've taken. i.e. the 20" target measured as .9 mil that I gave as an earlier example.

So, Lowlight, as chief spokesguy for the mil/mil (which I agree all in one system {the whole system} is the best, no matter which you choose), when ranging what do you see the target as? inches?, meter(or other metric breakdown)? Or do you use a pre-conversion of mils? like, "this tire on this vehicle is one mil@ 100m". Or, "one mil is standard from crotch to throat @ 100m". You then just proportionalize like I do with MOA. If you use this last method I think I may have a light coming on in my head as to why this is quick. By assigning an already known angular measurement to an object that you can break down when ranging later saves conversion. It's then a matter of reduction to get total range. I can see where that is quicker.

One of the arguments I've heard about ranging distance in meters is an easy conversion from meters to yards...if your brain still thinks that way. Meter to yards just add 10% 100m=110 yds. A little more difficult is yards to meters. Take away 10% and add back 1%. i.e. 100 yards = (100-10=90+1)=91m.

Anyways, I would appreciate your thoughts on that if I may.
 
Re: Why Mils over IPHY?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sobrbiker883</div><div class="ubbcode-body"> (IIRC the best score was 7/10 out of 54 shooters). </div></div>

Ummm, 8/10...thank you very much.
laugh.gif


Did it with a 3.5-15 NPR1 NF. Think I coulda done better with my p4fine S&B truth be told. I'm a mil guy.
 
Re: Why Mils over IPHY?

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">You've got to have a table or something to convert the linear measurement you see within the angular measurement you've taken. i.e. the 20" target measured as .9 mil that I gave as an earlier example. </div></div>

Mildot Master.
 
Re: Why Mils over IPHY?

The formula is actually inches * 27.778 / mils = range, so it's
20 * 27.778 = 555.56 / 1.1 = 505, .9 would put it a little past 600. A mil is 3.438 MOA, so if you are reading 4 MOA, you better not see .9 mil.

You could just think yards in the first place, then your math is the same.

.55 yards * 1000 / 1.1 mil = 500

Inside 600, I just flash mil if the target size is a torso or more. Figure the average adult is 30" throat to crotch. If he's more than 2.75 mil he's inside 300, 2.1 puts him at 400, 1.7 is 500 and 1.4 is 600. In between split the range and call it good. That will get you to within about 10 yards of actual, plenty shootable.

You can do that for any standard size you like, tape it to the stock and avoid the math altogether.

Since most shoot the same targets over and over, they get to know the sizes in a specific unit of measure and work from there. In reality, you'll need a table of common object sizes anyway, just log them in the desired units.

For example, how long is an 82mm mortar tube, or a DsHK? What's the width of a BMP-1? How about an RPG-7? I've just got them logged in yards (RPG-7 = 1.042 yards, PKM = 1.137 yards, etc.)

I can't imagine why one would range in meters and then convert to yards. Just log your dope in meters.

 
Re: Why Mils over IPHY?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rafael</div><div class="ubbcode-body">
I deserved that!
laugh.gif
</div></div>

Sorry, couldn't resist!
 
Re: Why Mils over IPHY?

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> A mil is 3.6 MOA, so if you are reading 4 MOA, you better not see .9 mil.</div></div>

A mil is 3.438 MOA.

One MOA at 100 yards is 1.047 inches. One mil at 100 yards is 3.6 inches.

3.6/1.047 = 3.438
 
Re: Why Mils over IPHY?

I meant to say 3.6 INCHES, since he's wotking in IPHY, I just typed MOA while reading his formula, my bad. I'll edit that.
 
Re: Why Mils over IPHY?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CoryT</div><div class="ubbcode-body">The formula is actually inches * 27.778 / mils = range, so it's
20 * 27.778 = 555.56 / 1.1 = 505, .9 would put it a little past 600. A mil is 3.438 MOA, so if you are reading 4 MOA, you better not see .9 mil.

You could just think yards in the first place, then your math is the same.

.55 yards * 1000 / 1.1 mil = 500

Inside 600, I just flash mil if the target size is a torso or more. Figure the average adult is 30" throat to crotch. If he's more than 2.75 mil he's inside 300, 2.1 puts him at 400, 1.7 is 500 and 1.4 is 600. In between split the range and call it good. That will get you to within about 10 yards of actual, plenty shootable.

You can do that for any standard size you like, tape it to the stock and avoid the math altogether.

Since most shoot the same targets over and over, they get to know the sizes in a specific unit of measure and work from there. In reality, you'll need a table of common object sizes anyway, just log them in the desired units.

For example, how long is an 82mm mortar tube, or a DsHK? What's the width of a BMP-1? How about an RPG-7? I've just got them logged in yards (RPG-7 = 1.042 yards, PKM = 1.137 yards, etc.)

I can't imagine why one would range in meters and then convert to yards. Just log your dope in meters.

</div></div>

CoryT,

Sorry about the math. I was trying to make the numbers jive for the example and bass-ackwarded it. In fact I just re-read my post and realized that the body measure of one mil was waaaay off. I was thinking downrange, not as a constant standard. At 100 yds it should read 8.75 mil?

But, your example does give a quick way to size up a man size target. Which is what you're generally using to range anyways as a tactical shooter. Use of the system and knowledge of intended targets tends to be a quicker conversion as you use it more. I guess it is like thinking in mil/mil-reduction then converting to overall distance.

CoryT,

Converting from meters to yards or vice-versa is sometimes necessary from maps. Sometimes I check range off of maps when terrain gives definitive points where I can guage from. Generally speaking with the MOA system I remain strictly in yards as the system is so close to IPHY that it just isn't feasible to convert to meters.

Now, from the entire discussion and others that I've pitched in from before I would say if all your target heights were given in metric the mil/mill would be much more friendly.

Lindy,

I'm thinking maybe I need to trade in the mil-dot calculator I got with my IOR. It doesn't have much of a table. Just sliding conversions. Maybe I should just go and get reacquainted with it.

Thanks for the input.
 
Re: Why Mils over IPHY?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sandwarrior</div><div class="ubbcode-body">

So, Lowlight, as chief spokesguy for the mil/mil (which I agree all in one system {the whole system} is the best, no matter which you choose), when ranging what do you see the target as? inches?, meter(or other metric breakdown)? Or do you use a pre-conversion of mils? like, "this tire on this vehicle is one mil@ 100m". Or, "one mil is standard from crotch to throat @ 100m". You then just proportionalize like I do with MOA. If you use this last method I think I may have a light coming on in my head as to why this is quick. By assigning an already known angular measurement to an object that you can break down when ranging later saves conversion. It's then a matter of reduction to get total range. I can see where that is quicker.



Anyways, I would appreciate your thoughts on that if I may.</div></div>

Well personally I have no reason to "mil" anything really, unless it is required in a competition and then, they usually give you eons of time because people are just really slow at it.

I mil targets weekly simply because we do it in class, and I can mil to the hundredth of a mil, which I always do when I have to do it long hand. So, I never mil something as .5, I mil it as .47 or .53, etc... it matters especially at distance. Mil'ing is a perishable skill and I do it alot, begrudgingly.

I consider using a scope to mil or just the mere act of mil'ing as a last resort and in my process I consider many other factors first...

1. I actually look at the target and say, "I think the target is more than 500 yards, less than 600 yards"... golden, I can shoot it with 550 and make a correction on my second shot faster and more accurate than most can mil in the first place. I actually practice so my second shot accuracy is more important than my first.

2. I pull my out laser and actually range the thing with my shiny piece of expensive kit. This is 2009 and not 1969, we have better shit and I like to use it. My batteries don't fail cause I change them and it's 1000% better and faster than trying to mil something.

3. I look at my range card, because prior proper planning prevents piss poor performance... its why we make them.

4. I go to my scope which I practice with simply because I teach it and people want to know how to mil and most should know how. So I spent a lot of time looking at targets with a reticle. It's a legacy skill that's an essential tool, but really, its the last one in my toolbox. I am versed in milling any which way you can envision and personally don't care which one i use. My personal favorite is the little cards with a size across the top and mils down the side... or a mil dot master. Both excellent little things, the card is some what faster.(maybe) If I had to, and my life was on the line I would be studying and working in centimeters and meters, and that's it, but I study and work them all, part of the game. Even when I am spotting for people on the line my spotting scope has a reticle and I mil shit, just cause I can.

Mil'ing is sloppy, inaccurate (for most), the farther out you go, the more the target matters, a lot, and mil'ing living human beings is hard as fuck. People don't present themselves full value and definitely don't stand still. We have even practiced mil'ing people in downtown kingsville on the court house roof and it's easier to say, "each block is 50 yards long, 100 yards, etc... and use that. Not to mention most of those engagements are inside the danger space of the system. Hold at the head, take out the hips, finish him off on the ground... why would I be risking mil'd shots past 600 yards when I am in no personal danger, If I can't guarantee a hit, I'm not wasting the shot. And I know what 600 yards looks like.

Lighter targets look bigger than actual size, darker targets smaller, angled targets etc... a lot matter to getting an actual number. I mil both the height and width given time and opportunity and never climb in the scope and die like a lot of people do.

Competitions that require precision mil'ing are different animals and I do the math long hand, both ways to the .00 and usually "THEY" give me the target size in inches... which I speak just fine. I also like movies, sunsets and flat shooting calibers to tip the odds in my favor.

So there you go...
 
Re: Why Mils over IPHY?

For competition purposes, the target sizes are limited, and often known in advance.

You're going to have to do the math for ranging, no matter what reticle you use, whether mils or MOA, except at relatively short distance where precision matters less. So, what reticle you have doesn't really matter.

A Mildot Master works for both mil and MOA based reticles, and is the fastest way to do that calculation.

Here is absolutely the fastest way to shoot a UKD target without a laser: Have precomputed a table which has the size of the targets in columns. For example, if you are shooting a match where all the targets are LaRue plates, then you need two columns, one for the 11.75 inch width, and one for the 22 inch height.

The rows of the table are image sizes - I use 0.1 mil increments, and interpolate between them if it's a good day, and I can measure to the nearest 0.05 mil. With a MOA-based reticle, the rows might be 0.25 MOA.

The data in the table are not range, but elevation for the appropriate conditions, i.e., temperature and barometric pressure. If you are shooting holdoffs based on the reticle, rather than dialing elevation, so much the better.

So, you measure the target in your scope, look at the table to determine the correct hold, or have your spotter read you the correct hold, apply the correct hold, and smoothly press the trigger to the rear.

And a first focal-plane scope gives you an advantage.

Building that table takes a bit of work, since you have to build a different one if temperature and pressure are very different. But it's the fastest way to do the chore.

Second fastest is to use a Mildot Master, and have your holds for distance memorized.


 
Re: Why Mils over IPHY?

Lowlight and Lindy,

Thank you both for taking the time to respond to my questions. I have a few mil-dot scopes but they are all MOA adjusted. When USO came out with the mil/mil I thought awesome! But then the nagging question always came back to me about converting target height in inches to mils. Because I'm one of the slow people using mils.
I had, by the way, already bought an MOA scope from USO. I love using that as it seems to me that converting isn't so hard. I am somewhat cheap though and haven't spent any money on a laser rangefinder. That'd certainly be an easier way to go. I'm also a huge fan of flatter shooting calibers. In fact my .308 barely sees much action anymore at all, unless I'm trying out new .30 cal bullets. Also, the longest point blank range to zero on for the smallest type target you might encounter. Typically, my rifles are zeroed @300 yds. I then hold 3 /12"-6" low, depending on which rifle I shoot, for 100 and 200.
 
Re: Why Mils over IPHY?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: NineHotel</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sub2.908cm/100m</div><div class="ubbcode-body">

BTW, you might wish to do a little research and revise your chronology re: "the(y) were invented hundreds of years apart".
wink.gif
</div></div>

203 years apart to be exact. That's "hundreds" by my definition - yours? </div></div>

In light of LL and then Lindy's practical, to the point and helpful posts, I won't bother with a response...

Believe what you wish, es macht nicht
smirk.gif
...
 
Re: Why Mils over IPHY?

Hi together
first of all, sorry for my terrible english, I hope that you understand what I write.
I don't know the IPHY but I know mils and moa click sistem.
I work in meters (mt) not in yards.

MOA sistem
1 moa is 2,91 cm (centimeters) at 100 mt
1 moa is 5,81 cm at 200 mt (2,91 x 2)
1 moa is 14,6 cm at 500 mt (2,91 x 5)
every time you need a calculators for extract the corret moa/distance

MIL sistem
The sistem is metric
1 mt = 10 cm (centimers)
10 cm are 1 mil at 100 mt
1 mil at 100 mt are 10 clicks of a torret of 1 cm (0,1 mrad) click.

1 mil = 10 cm at 100 mt
1 mil = 20 cm at 200 mt
and gone to
1 mil = 100 cm (1 mt) at 1000 mt (1 Km -Kilometers-)

The sistem work in decimal
If my spotter say me to correct my shoot with 1,3 mils up, I can choose if correct with the reticle (hold off) or with the torret click, in thi second situation I turn 13 click if at 0,1 rad (1 cm). If I and my spotter work with sniper scope and spotter scope both with the reticle on the FFP there aren't problem for the different magnifications between the two optics or not complicate mind aritmetics operations: 1,3 mils are 1,3 mils for both.
The mils system is very fast and simple, but for a good work is necessary that the torret of the scope, the reticle and the spotter scope work and speak at the same language. If You prefer work in MOA the mind aritmetics problem are a lite bit complicate and not so natural. You can speak the same language with the reticle and the torret click but not with the spotter scope, it works only in mils.
KISS
target at 650 mt
1 mil at this distance is 10 cm x 6,5 = 65 cm .....easy
1 MOA at this distance is 2,91 cm x 6,5 = ...... you need a calculator

The MOA sistem is perfect if you work with 1/5 moa, 1/8 moa for bench rest competitions or precision shooting competitions, but if you are a hunter or a military the mil sistem is the winner

Another think, with the mil-dot or TMR or similar you can work great in hold-off at every distance. Last week I shoot at 800 mt with my Remington 700 Police DM with NXS 5,5-22x56 setting at 100 mt and Fiocchi USA .308 180 grs cartriges. At 11x, hold-off at 5 mils down I was in the center of the target. This isn' t possible with MOA reticle.
Sorry, sorry sorry for my english

www.italiangallinagoshooting.org
 
Re: Why Mils over IPHY?

1moa, Your english is much better than my Italian, and better than some of the the other forum members here in the states.

From what you stated about your 800 meter shot, you dialed down to 1/2 max power with a second focal plain scope so in effect were holding 10 mils. I can do 800 meters (what around 866 yds) with a US optics moa reticle just fine, and on 17 power to boot.

Being raised with the metric system would make the choice easy, but we are blessed with both systems and have many choices.
 
Re: Why Mils over IPHY?

Half of what .1 mil would be which is .36" so .05 mils would be .18" at 100 yards.
 
Re: Why Mils over IPHY?

1 mil at 100 yards is 3.6 inches
.5 mil is 1.8 inches
.10 mil is .36
.05 mil is .18
got it

gracias
 
Re: Why Mils over IPHY?

Bronco said:
1moa, Your english is much better than my Italian, and better than some of the the other forum members here in the states.

+1
 
Re: Why Mils over IPHY?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lindy</div><div class="ubbcode-body">For competition purposes, the target sizes are limited, and often known in advance.

You're going to have to do the math for ranging, no matter what reticle you use, whether mils or MOA, except at relatively short distance where precision matters less. So, what reticle you have doesn't really matter.

A Mildot Master works for both mil and MOA based reticles, and is the fastest way to do that calculation.

Here is absolutely the fastest way to shoot a UKD target without a laser: Have precomputed a table which has the size of the targets in columns. For example, if you are shooting a match where all the targets are LaRue plates, then you need two columns, one for the 11.75 inch width, and one for the 22 inch height.

The rows of the table are image sizes - I use 0.1 mil increments, and interpolate between them if it's a good day, and I can measure to the nearest 0.05 mil. With a MOA-based reticle, the rows might be 0.25 MOA.

The data in the table are not range, but elevation for the appropriate conditions, i.e., temperature and barometric pressure. If you are shooting holdoffs based on the reticle, rather than dialing elevation, so much the better.

So, you measure the target in your scope, look at the table to determine the correct hold, or have your spotter read you the correct hold, apply the correct hold, and smoothly press the trigger to the rear.

And a first focal-plane scope gives you an advantage.

Building that table takes a bit of work, since you have to build a different one if temperature and pressure are very different. But it's the fastest way to do the chore.

Second fastest is to use a Mildot Master, and have your holds for distance memorized.</div></div>