Advanced Marksmanship Converting Ballistic data into Mills

[kentactic]

hey guys its my first post.

my question is perhaps a common one. everyone always says that mills isnt a unit of measure and shouldnt be thought of as such because its always changing. but when one is converting a ballistic chart into mills from inches how do you convert it without breaking it down into its measurment form to adjust for said ranges?

 

[Lindy]

Re: Converting Ballistic data into Mills

If you are talking about converting inches of drop into mils, here's your formula:

<div class="ubbcode-block"><div class="ubbcode-header">Code:</div><div class="ubbcode-body ubbcode-pre" ><pre>
drop (inches)
mils = ------------------------------------
3.6 * (distance in yards/100)
</pre></div></div>

For example, if you have a drop of 400 inches at 1000 yards, in mils that would be:

mils = 400 / 3.6 * (1000/100)

mils = 400 / 36 = 11.11

 

[kentactic]

Re: Converting Ballistic data into Mills

yeah i understand the formula to convert it but i was just curious if theres another way.

so what your saying is theres no way around it. you must convert to mills from inches at one point or another.

would it be best to just convert the inches to mills on my ballistic charts as apposed to converting them on the fly?

appreciate the quick replys

 

[Lindy]

Re: Converting Ballistic data into Mills

There is no way around it - but what would be better is to start using a ballistic program which will output mils. There really is no use for drop in inches.

http://www.jbmballistics.com

There are others.

 

[Guest]

Re: Converting Ballistic data into Mills

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lindy</div><div class="ubbcode-body"> There really is no use for drop in inches.</div></div>

Unless you live in a IPHY world, like some of us.

 

[kentactic]

Re: Converting Ballistic data into Mills

that looks a little too fancy for my style. id rather just do the math one time and be done with it as far as a general guidline drop/windage chart.

 

[ckirkc]

Re: Converting Ballistic data into Mills

??? It's not very fancy. Go to jbmballistics.com and figure it out. From there you can print out range cards and drop charts. You are wanting to learn the precision rifle game....your style is going to be ballistic calculators.

 

[mberry223]

Re: Converting Ballistic data into Mills

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lindy</div><div class="ubbcode-body">There really is no use for drop in inches. </div></div>

Lindy, when I am not looking through a reticle, I think in inches much more than I do mils. Do you not think there is value in knowing your bullet drop in inches so that you may estimate your holdover, especially if you may find your self shooting a rifle without a standard mildot?

Also, if you do not have a FFP scope I believe it is easier for the eye to estimate a holdover based on inches (assuming you are not shooting on the correct magnification).

I guess if you know one you can always quickly convert to the other, and that is the point of understanding mils completely.

I always learn from your posts, so I am interested in your view point and discussion.

Thanks!

 

[Rob01]

Re: Converting Ballistic data into Mills

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Gunfighter14e2</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lindy</div><div class="ubbcode-body"> There really is no use for drop in inches.</div></div>

Unless you live in a IPHY world, like some of us.</div></div>

No reason then either as if you run the chart in IPHY then it doesn't come up in inches. It comes up as drop in IPHY. Doesn't read 300 for a 300 inch drop at 1000 yards. It reads 30 so you can dial that on your knob or hold in your reticle.

Winmagfrog, I'm not Lindy but for me I never think in inches. I will use the reticle if looking through the scope and actually I never shoot without looking through the scope so why do I need to know inches?

Even a standard duplex can be used like that no matter FFP or SFP. You see where in the reticle you hit from your POA and then correct for follow up shot. Why does it matter how many inches low you hit?

If I am looking at a target with an optic with no reticle like a spotter or binos and calling a correction I will use the target size. Like "hold two target widths right" or "hold top of target" . Use the correction from the POA of the shooter but it is easier if you know the person you are spotting for to have good communication or a reticle in the spotter.

 

[Guest]

Re: Converting Ballistic data into Mills

I've never used anything JBM, and have always used IPHY even when some stuff I had was true MOA. Back in the mid 70's I started using Serria's drop charts which were all in inch's. Even today the latest one I have is in inch's as well.

Even though I don't use their load book data anymore, the disk I still use at times, is in inch's of drop at the target but also gives + or - for any range, and to date it's been right on. It also works with the IPHY USO reticles an EREK knobs I use. Everything I have size data on is given in inch's, and I still like to test myself every now an then, followed up by Mr. Leica's input or ASM1's Swarovski. I no longer use anything but IPHY and every now an then I find others that way as well.

There is more than one way to skin a cat and I've found threw the years what works for other's may not be my choice for my style of closure. It mattered little how you completed the task, just as long as the task was completed. Old habit's die harder with age, and I have both haunting me.

 

[kentactic]

Re: Converting Ballistic data into Mills

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ckirkc</div><div class="ubbcode-body">??? It's not very fancy. Go to jbmballistics.com and figure it out. From there you can print out range cards and drop charts. You are wanting to learn the precision rifle game....your style is going to be ballistic calculators. </div></div>

my mistake i thought you were reffering me to that electronic device that instantly calculates for humidity and all that jazz.

thanks for the link

 

[mberry223]

Re: Converting Ballistic data into Mills

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rob01</div><div class="ubbcode-body"> Winmagfrog, I'm not Lindy but for me I never think in inches. I will use the reticle if looking through the scope and actually I never shoot without looking through the scope so why do I need to know inches?

Even a standard duplex can be used like that no matter FFP or SFP. You see where in the reticle you hit from your POA and then correct for follow up shot. Why does it matter how many inches low you hit?

If I am looking at a target with an optic with no reticle like a spotter or binos and calling a correction I will use the target size. Like "hold two target widths right" or "hold top of target" . Use the correction from the POA of the shooter but it is easier if you know the person you are spotting for to have good communication or a reticle in the spotter.

</div></div>

I agree with most of what you are saying, especially for correcting a shot. I am mainly talking about shooting holds, as that is what I usually do.

Maybe I am not illustrating my point well enough. Let me just ball park something and say that I am looking at a deer at 320 yards and I have a 100 yd zero on my gun. I know that the round is going to drop about 10 inches from my zero. To me, it is much easier to know it in inches and then either convert that to a mil holdover or just a guess (a little over his back).

I suppose that if I had been brought up doing things differently, I could imagine my hold overs in mils, rather than inches and then converting.

It is probably a lot like learning a second language. When you first learn, you change the words to English in your mind. As you become more fluent you no longer need to do the mental conversion.

Mostly, I am bored and at the in-laws, so I'm just thinking out loud...

 

[Lowlight]

Re: Converting Ballistic data into Mills

Basically, because mils are smaller it is a bit easier to memorize than, inches or MOA.

if you know,

200 = .5 Mils

300 = 1.5 Mils

400 = 2.2 Mils

On your turrets, you have the same thing on your reticle. So dialing 1.5 mils for a 300 yard shot is the same as holding 1.5 mils on your reticle.

For those with MOA turrets we do, .25 mils on the reticle = 1 MOA on the turrets... so 1 Mil = 4 MOA at the turrets. Any range.

Essentially you only have to remember from 200 to 1000 yards, which is .5 to about 11 Mils, maybe 11.5 mils... easy number to remember.

If you are sitting in a deer stand and a deer appears at 320 yards, you can simply hold 1.6 mils high and call it a happy day because it exactly matches your dope and is not an approximation of what you think 10 inches 320 yards away. Think of it this way, approximating distance that far away is why women are bad drivers, they keep on getting told 6" = 9" so their estimations are always a bit off.

Matching turrets means a true value and not an estimation of a value across a distance.

 

[LSOSGT1109]

Re: Converting Ballistic data into Mills

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">Basically, because mils are smaller it is a bit easier to memorize than, inches or MOA.

if you know,

200 = .5 Mils

300 = 1.5 Mils

400 = 2.2 Mils

On your turrets, you have the same thing on your reticle. So dialing 1.5 mils for a 300 yard shot is the same as holding 1.5 mils on your reticle.

For those with MOA turrets we do, .25 mils on the reticle = 1 MOA on the turrets... so 1 Mil = 4 MOA at the turrets. Any range.

Essentially you only have to remember from 200 to 1000 yards, which is .5 to about 11 Mils, maybe 11.5 mils... easy number to remember.

If you are sitting in a deer stand and a deer appears at 320 yards, you can simply hold 1.6 mils high and call it a happy day because it exactly matches your dope and is not an approximation of what you think 10 inches 320 yards away. Think of it this way, approximating distance that far away is why women are bad drivers, they keep on getting told 6" = 9" so their estimations are always a bit off.

Matching turrets means a true value and not an estimation of a value across a distance. </div></div>

6"?? I've always just told my wife that 4" is as big as they come! LOL

 

[nw911guy]

Re: Converting Ballistic data into Mills

Interesting. I may just learn this yet.

I think, as Gunfighter alluded to, that when you spend 30+ years having inches drilled into your skull, mils can seem a bit foreign, sort of like learning to convert to metric measurement.

 

[Rob01]

Re: Converting Ballistic data into Mills

Even when I ran MOA knobs and mil reticles for many years before I switched to all mils I never thought in inches. I ran charts in MOA and mils as that is what my scope was set up to work with. Not inches.

The only place inches comes into anything in my shooting for me is in a target size when I am ranging a target but that is a separate operation from dialing or holding elevation/windage.

Gunfighter if you are set in your inches way and it works for you then that's cool but it would be better for someone looking to learn to learn mils or MOA or IPHY without having to convert inches to the actual dope you would dial on the rifle or hold in the reticle. It will make life easier on them.

 

[Guest]

Re: Converting Ballistic data into Mills

There must be something missing here. IPHY is inchs anyway you look at it, and I never said I do comeup's in inchs. All my comeups are in IPHY with a 100yd zero. The only time I even look at drops in inchs is when a new to me load an bullet is being set down range for the first time. Then I look hard at the 600yd dope that was used vs what the disk said it should be and adjust if needed. All my up and wind holds are taped to every stick and it's all in IPHY.

All my TO&E sizing data for ours or theirs was/is in inch's, as that's the way Uncle issued it, and the Civie way it's listed in every chart I've ever seen or had. That inch data is for ranging only, not drops. Gear, weapon's, doorway's, an street sign's ect, rarely change size, people come in all sizes.

Mil's are not foreign to me, but everything I've learned over the years and most every thing used for ranging is/are still given in inch's. LRF's are great but something I don't hold faith in when push comes to shove, as I've seen more stuff take a dump at the worst time. It's yet another tool w/battery's that has to be toted, and when it all goes to shit I trust my brain over gear. Then there are places a LRF will not work do to closer items they lock on to, target angle, surface ect. Yes, I know how to over come most of that but, the reticle, is all ready on the target, why not learn it then just holdover an shoot. Cut's both movement and time down.

I think many times words on a page are misleading as to the intent of the type'r, let alone the reader.

If guys want to use their thumb, pinky, .308 bullet, pencil lead, or the front sight of their weapon on a 18" wide object to range, like we were taught long ago I don't really care. I doubt this basic task is even being taught any more. As long as we know options are out there we have choices. It's up to the user to know what works best for him, not the crowd. Because most of the time unless your in a far away land all dressed the same, your on your own. Even when dressed by others you still maybe on your own, and many have found that out the hard way. This is why folks need to use what works for them, and learn it well.

 

[Lowlight]

Re: Converting Ballistic data into Mills

Gunfighter,

it is really about time and accuracy... and honestly, it's not 1978 anymore, stuff is not only listed in inches from Uncle Sugar or anyone else. They list it in mils.

Accuracy wise, as I stated it's not a "guess" educated or otherwise. There is no comparing objects to each other, that takes time. You have to make a decision to look and think, how big is that, or even how big is that compared to it's surroundings... it's why ranging targets by any means other than a laser is a legacy skill and not an primary asset. Sure you can look first and say, "I think the target is 400 meters / yards away" and then engage, inside that range chances are you are fine. In fact inside 600 yards any competent shooter should be able to get a second round hit in 3 to 5 seconds from the initial shot without any aid or reference. However if you think you'll mil, or range with your reticle in inches the battle has already passed you.

LRF have progressed since the 80's and 90's, now they have highly reliable units that don't eat batteries that can accurately range to 10,000m in single push simple based off where the reticle of the scope is pointing. the unit is small, mounts between the Objective bell and the Turret Saddle and displays above your elevation turret. It's not a liability but a primary asset... used first and only in many cases. These units cost in excess of $15k to make sure they work right, and they are darn sure more accuracy than any human ranging.

As you said the reticle is already on target, hold over and use it... right but with actual dope and not an approximate estimate of your dope.

Tell me what happens when the target is behind a wall and only part of it is exposed and putting accuracy fire on your troops ? Do you hold over with an approximate number in hopes of hitting a sub moa target or do you say, my hold for 430 yards is 2.6 mils and hit the target ? What is that over the target in the air ?

Uncle sugar doesn't use a IPHY reticle he use an Mil reticle so knowing this in mils is a smarter solution... not the only solution but the smarter one.

 

[Guest]

Re: Converting Ballistic data into Mills

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">so knowing this in mils is a smarter solution... not the only solution but the smarter one. </div></div>

Here again we are looking at this from two different view points, your's being present day Military useage, mine past and now square only.
No, you do not see a crack forming. I started w/inchs and will go out that way.

As for the guy at 430yds, with my .308 he's only a 8.75 reticle hold away from his maker, with the win mag it's 5.8

 

[Lowlight]

Re: Converting Ballistic data into Mills

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Gunfighter14e2</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">so knowing this in mils is a smarter solution... not the only solution but the smarter one. </div></div>

Here again we are looking at this from two different view points, your's being present day Military useage, mine past and now square only.
No, you do not see a crack forming. I started w/inchs and will go out that way.

As for the guy at 430yds, with my .308 he's only a 8.75 reticle hold away from his maker, with the win mag it's 5.8</div></div>


Well good luck with that, I would rather read / know what the right dope is, than guess what 8.75" looks like 430 yards away when someone is shooting back at me. The faster I solve the problem the better, having to adjust that hold because I am approximating it seems a bit silly. On minute of man anything works, but when it's partially obscured from view, or moving that approximation becomes more and more of a liability.

Set in your ways I understand, it is what it is, but I wouldn't be claiming it's anything more than a hold over from a by-gone era. Every day we have people who show up to either training or competition with an "idea" of what has been working for them on their own, at their home range. As soon you ask them to put it in practice on something other than prone, slow fire, it all falls apart and they start to wonder why it worked so well for them at home. That goes for things as mundane as ranging with inches, still haven't found the person who can solve a majority of the UKD problems successfully with inches. Especially under time.

 

[Guest]

Re: Converting Ballistic data into Mills

I don't see where your coming up with I'm holding air, each MDMOA reticle vertical is subtended to 60 IPHY and wind is a total of 80. What am I missing?

 

[SierraOne1]

Re: Converting Ballistic data into Mills

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">
For those with MOA turrets we do, .25 mils on the reticle = 1 MOA on the turrets... so 1 Mil = 4 MOA at the turrets. Any range.
</div></div>

Lowlight, magnification affects this ratio the same as it does for ranging a target, correct (ie, FFP Vs SFP)?

 

[Lowlight]

Re: Converting Ballistic data into Mills

Yes. the mils have to be correct for this to work...

Gunfighter,

Matching the reticle / turrets is an non-issue, however it makes you very unpopular with others as most have a mil type reticle over MOA or even IPHY.

But if your system matches it's a non-issue really which you use, but again, the thinking is in much higher numbers with fractions, as in 8.75 instead of 2.6, it makes it harder to memorize.

 

[SierraOne1]

Re: Converting Ballistic data into Mills

Rgr....Thx.

 

[Guest]

Re: Converting Ballistic data into Mills

I fully understand the need for everyone wearing the same rags to be on the same page when it all starts. The need for the reticle to match the knobs as all mine do, is a very simple working system. I went to 1/2 IPHY EREK's with the MD's as the retical gets me to 40 alone, then if needed I can spin up 50 in just over one full turn, then add the rest with the reticle. If I need more than 3/4's of that total, I'm past FUBAR'ed anyway.

The guys I would aline with if needed, to a person, are either a MOA or IPHY shooter. The bulk of us are within 8 years of age diff with a few 20-30 somethings thrown in, who have drifted to MOA/IPHY as well.

As to the number difference it's easier for me to break down the MDMOA into 1/2 or(1/4 if needed)IPHY's as she is subtended by one IPHY both ways to full read. The larger numbers are just numbers to remember, just like Mil's and splits there of.

If I was just using a duplex only, an no LRF, even knowing how to run it in reverse(rusty on this but not corroded)yes I'd get sideways on reticles an glass, an slip into 2011. With USO an NightForce and others going the Burger king way, I'll go out like I came in.

Again, I fully understand were your coming from, and I hope you do me as well. It's a long way's from just moving a Cam, an mathing the numbers(if not 30")with paper an pin, but like alot of folks say,...it is want it is.