Advanced Marksmanship How to convert inche drop at 1000 Yards to Mils

Aside from any marksmanship or wind estimation errors, you're missing because you're introducing errors from completely unnecessary arithmetic.

I will admit that the one time I went to the 500 yard range, I probably shouldn’t have. I wasn’t ready for that. I don’t know my ammo and how my rifle shoots it well enough to have accurate drop info for that distance. I put the ammo data into the Hornady ballistics app and used the adjustments it gave me. However, I know that’s not 100% accurate. I haven’t shot paper any further than 200 yards with anything but cheap Winchester white box 6.5cm.
 
Because my targets are in inches. So if I shoot 2 inches low at 100 yards then I know I can dial up 6 clicks or .6mils. I don’t have a chart for my ammo for each range because I’m still practicing basic marksmanship skills and using whatever cheap ammo I can find.

I suppose I can print targets in cm’s and then forget the conversion. But since the range near me has target placement at yards, my targets are inches, and I have another rifle with an moa scope (soon to change to mils), I guess it makes sense to me to read the target in the inches that it’s in and remember the rough conversion to mil adjustments.
Just use your reticle.
 
👍

I haven’t taken the time to study the reticle and the measurements of the marks on it yet. I’ll definitely add that to my to do asap list!
If your scope adjusts in mils and your reticle is in mils then it tells you exactly how much to dial. No need for inch conversion or centimeters or whatever.
 
Remember using your reticle, when it says your off by whatever mils that’s a direct relation to what you should dial regardless of distance.

Get a ballistic app and plug in your bullet info and it will give you your drops in mils or MOA for you instead of shooting at each distance to get your drops. You might have to true the muzzle velocity and BC but it’s a lot easier than trying to shoot to get drops at each distance.
 
Get a ballistic app and plug in your bullet info and it will give you your drops in mils or MOA for you instead of shooting at each distance to get your drops. You might have to true the muzzle velocity and BC but it’s a lot easier than trying to shoot to get drops at each distance.
Not sure I understand what you are saying.

You need to shoot actuals to true the results of your ballistic calculator. The actual drop is all the bullet knows, and all that matters. Once you know your actuals, you can adjust the MV and/or the bc as appropriate so that the predicted drop equals your actuals.

If this is what you meant, I apologize in advance
 
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Not sure I understand what you are saying.

You need to shoot actuals to true the results of your ballistic calculator. The actual drop is all the bullet knows, and all that matters. Once you know your actuals, you can adjust the MV and/or the bc as appropriate so that the predicted drop equals your actuals.

If this is what you meant, I apologize in advance
So your ballistic app will give you firing solutions for whatever distance you want if you put in your information correctly on BC, bullet weight, velocity, sight height over bore, and proper environmental data. This is generally pretty close to accurate.

After you do this go to the range, go to 400-500 yards or so and see what the ballistic app tells you for that range and dial that. Shoot and see if it hits where it’s supposed to. If it doesn’t then use your reticle to measure how much more you have to dial. Shoot again and see if it’s on. If it is then change your muzzle velocity in the app until the mil value for the drop it gives you equals your actual dialed amount you are now using.

Make sure your environmental information is entered accurately for when you’re shooting as well as the app will use this to give you more accurate firing solutions.
 
Because my targets are in inches. So if I shoot 2 inches low at 100 yards then I know I can dial up 6 clicks or .6mils. I don’t have a chart for my ammo for each range because I’m still practicing basic marksmanship skills and using whatever cheap ammo I can find.
If you're talking about zeroing at 100 yds with a target that has an inch grid, yes you can do it that way. Or you can learn how to adjust using the reticle subtensions which is faster and usable at any distance without math.

I suppose I can print targets in cm’s and then forget the conversion. But since the range near me has target placement at yards, my targets are inches, and I have another rifle with an moa scope (soon to change to mils), I guess it makes sense to me to read the target in the inches that it’s in and remember the rough conversion to mil adjustments.
Or you can learn how to use your reticle to measure the angular offset and apply the correction without math and without concern about the actual distance to target.

You really need to stop defending why you do what you do. We're trying to teach you and your pushback makes you look bad.
 
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After you get your muzzle velocity trued you should then shoot out to wherever your bullet is now mach 1.2-1.3 or so (I don’t remember the actual speed off hand) and do the same thing except this time you adjust BC to get the drops to match.
 
If you're talking about zeroing at 100 yds with a target that has an inch grid, yes you can do it that way. Or you can learn how to adjust using the reticle subtensions which is faster and usable at any distance without math.


Or you can learn how to use your reticle to measure the angular offset and apply the correction without math and without concern about the actual distance to target.

You really need to stop defending why you do what you do. We're trying to teach you and your pushback makes you look bad.

Using the reticle definitely makes sense. I’ll study the reticle numbers and use that. I apologize if it seems as if I’m defending bad methods but that’s not my intent. I am explaining why I do what I do so that my method can be fixed.

I definitely appreciate all the feedback and am drinking through a fire hose at the moment to learn as much as I can.
 
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Using the reticle definitely makes sense. I’ll study the reticle numbers and use that. I apologize if it seems as if I’m defending bad methods but that’s not my intent. I am explaining why I do what I do so that my method can be fixed.

I definitely appreciate all the feedback and am drinking through a fire hose at the moment to learn as much as I can.
Things can get confusing pretty fast if you’ve got no experience with it. Just be systematic about it. Learn your gear, learn how to use it properly. Download something like Hornady 4dof or Applied Ballistics and just sit on the couch and watch a few YouTube videos on it and play with it and get familiar with it. It’s really not too hard and certain things can over complicate it quickly. Just trust the system and method. But yes, for sure learn your reticle values. You pay plenty money for the convenience of using these things, just take time to learn them.
 
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Another thing to consider is to shoot better ammunition. If you shoot something like Hornady they, like most, will publish their highest BC on the box which is usually only accurate out to around 300 yards or so. As the bullet slows the BC changes. Hornady publishes three different BC’s for their bullets on their website. Use their lowest BC published which is for the bullet around mach 1.3 I believe. This and an accurate muzzle velocity should get you very close to where you need to be.

ETA: Now that Thanksgiving is over I have had the opportunity to check and Hornady publishes the BC for their bullets at mach 2.25, 2.0, and 1.75
 
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So your ballistic app will give you firing solutions for whatever distance you want if you put in your information correctly on BC, bullet weight, velocity, sight height over bore, and proper environmental data. This is generally pretty close to accurate.

After you do this go to the range, go to 400-500 yards or so and see what the ballistic app tells you for that range and dial that. Shoot and see if it hits where it’s supposed to. If it doesn’t then use your reticle to measure how much more you have to dial. Shoot again and see if it’s on. If it is then change your muzzle velocity in the app until the mil value for the drop it gives you equals your actual dialed amount you are now using.

Make sure your environmental information is entered accurately for when you’re shooting as well as the app will use this to give you more accurate firing solutions.
Yes, to most of this, but truing your velocity generally requires DOPE at distances past 600 yards. I shoot factory ammo, so I use the values on the box as starting points and go from there. I don't generally find the results to be "accurate." It is within 0.3-0.5 mils at longer distances. If you have chronograph data for MV with good SD values and enter those into an app, it is better. The Kestrel measures the environmental parameters, so those are generally accurate.

You always need to true to get accurate results.
 
Yes, to most of this, but truing your velocity generally requires DOPE at distances past 600 yards. I shoot factory ammo, so I use the values on the box as starting points and go from there. I don't generally find the results to be "accurate." It is within 0.3-0.5 mils at longer distances. If you have chronograph data for MV with good SD values and enter those into an app, it is better. The Kestrel measures the environmental parameters, so those are generally accurate.

You always need to true to get accurate results.
I covered truing BC in a post after that. I true velocity under 600 yards and true BC over 600 yards.
 
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Don't forget there are instances of people still shooting paper or e targets at distance so they get an inch of moa offset in many cases they need to convert

Not everybody is looking for paint off steel plates

There are short cuts to doing anything...
But come on people...
if we are here to true our data...
DO THE MATH already and get it right! because rounding is always a compounding error and will continue to grow more and more. It's not that hard to use actual numbers.

The rounding and rules of thumb are for field expedient conversions to get close enough to put bullets on targets for more accurate analysis.
 
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Don't forget there are instances of people still shooting paper or e targets at distance so they get an inch of moa offset in many cases they need to convert

Not everybody is looking for paint off steel plates

There are short cuts to doing anything...
But come on people...
if we are here to true our data...
DO THE MATH already and get it right! because rounding is always a compounding error and will continue to grow more and more. It's not that hard to use actual numbers.

The rounding and rules of thumb are for field expedient conversions to get close enough to put bullets on targets for more accurate analysis.

Good point. And I’ll add, if you’re walking or driving back and forth to check the hits on paper then you certainly have the time to actually do the proper math.

For mils, I think a lot of new shooters get put off thinking you can’t use mils with inches, or that it’s complicated math to do so, which it’s not any different than using MOA the proper way.

And if you want to use a rule of thumb to get you close then just realize that 3 clicks on a mil scope is about an inch at 100 yards, the same as 4 clicks on a 1/4 MOA scope is.
 
If simplicity and ‘1 inch is close enough’ then might I suggest using the Gravity Ballistics app? It really does simplify the process of getting hits on paper and then make precise corrections based on angular measurements that you can actually just read through your scope. Then the precise adjustments can be made and that info can be used to true your ballistic calculator. Or it can be printed and laminated for a range card that won’t have batteries to worry about. Basically you use the calculator to solve for data while sitting at a nice shooting bench and the data can be used without much thought in the field
 
Gravity Ballistics...BINGO.
Zero at 100 yds and you can get , almost, center hits at any distance you want out to 1000 yds.
It is an easy accurate system that works with mil and moa.
Kudos to Marc Taylor for coming up with such a brilliant system.
 
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Because my targets are in inches. So if I shoot 2 inches low at 100 yards then I know I can dial up 6 clicks or .6mils. I don’t have a chart for my ammo for each range because I’m still practicing basic marksmanship skills and using whatever cheap ammo I can find.

I suppose I can print targets in cm’s and then forget the conversion. But since the range near me has target placement at yards, my targets are inches, and I have another rifle with an moa scope (soon to change to mils), I guess it makes sense to me to read the target in the inches that it’s in and remember the rough conversion to mil adjustments.
Best way to fix your thinking quickly.

Am I in touching distance of the target?

If yes, use it is OK to use linear measurements (inches, cm, thousanths of an inch).

If no, only think and talk angular units as measured by the reticle or given by a ballistic calculator. You have a calibrated ruler 3" in front of your nose (note your nose is in touching distance). Use it.

Don't think clicks. Think in the number.

1.5 moa low? Add 1.5 moa.
.8 mils right? Add .8 mils.
 
Is the gravity ballistics app worth the $5 over the free Hornady app?
Absolutely.
I learned/used Gravity Ballistics last summer at a precision rifle course with Frank and Marc and hit the waterline center target within 2 shots every 100 yds almost every time out to 1240 yds.
It is simple and accurate.
It doesn't care about velocity, or BC.
Get a good zero at 100 yds and work the numbers from there.
They are accurate and easy.
Yes, I am completely sold on Gravity Ballistics because once you get your numbers, you can then fine tune your ballistic app for your specific rifle by modifying velocity and BC to match the GB numbers to be totally accurate.
 
I downloaded the app but have a couple questions. Is it all in moa or inches for the drop?

Also, it doesn’t account for velocity or any environmental factors. Does adding a 100yd zero and a single 200 yard drop really make everything else accurate on a range card?
 
I downloaded the app but have a couple questions. Is it all in moa or inches for the drop?

Also, it doesn’t account for velocity or any environmental factors. Does adding a 100yd zero and a single 200 yard drop really make everything else accurate on a range card?
It works for mil or moa.
That's the beauty of it.
It is based on gravities effect on the bullet,
Velocity, BC don't come into play at all.
Once you have a good 100 yd zero, you add 1 mil or moa to get close to 200.
Then take your 200 data and multiply it by 2 to get 300.
Then follow the sequence..
300 data x 1.75 = 400
400 data x1.45 =500
500 x1.45 = 600
600 x1.3 =700
700 x1.25 = 800
800 x1.24 = 900
900 x 1.22 = 1000

It's really easier than it seems on paper.
Others can explain it better than me, but it does work.
 
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I downloaded the app but have a couple questions. Is it all in moa or inches for the drop?

Also, it doesn’t account for velocity or any environmental factors. Does adding a 100yd zero and a single 200 yard drop really make everything else accurate on a range card?
The X factor is your try number. It is based off of your 100 yard zero. It is strictly math that will give you an adjustment in moa or mil as your case may be. NO inches involved. Only measured in angle. No need for velocity either. Honestly it’s so simple that it will astound you.
 
I downloaded the app but have a couple questions. Is it all in moa or inches for the drop?

Also, it doesn’t account for velocity or any environmental factors. Does adding a 100yd zero and a single 200 yard drop really make everything else accurate on a range card?
I don’t think it will give you anything. You’re gonna have to collect all that data for yourself by going out and shooting in those different conditions and distances. I’m not saying it isn’t good, but to me it seems limited and it’s something you “can” use instead of a ballistic calculator, but it’s not going to have near the functions or convenience of a ballistic calculator.

Yall let me know if I’m wrong and if I am let me know how it makes these corrections because I would like to learn. I keep a gravity ballistics worksheet in my data book just in case I ever need it, and I think it’s great for what it is. But that’s it. Unless they’ve built something into the app that I’m not aware of, which is possible I suppose.
 
Couple thoughts on the GB app. I watched lowlights YouTube video which explained it well. However, why are the x-factors adjustable by the user? When would I wanna adjust them? Also, I’m assuming this math only accounts for a rifle that is on the same elevation as all the targets?

I’m curious as to how this math works. Where did the x-factors come from? How were they derived?

I read through the thread posted above and it stated that the numbers came from a pool of data from many shooters. But it doesn’t describe details.

I will also comment that it would be nice if the app had more useful features (resetting x-factors to default if an newb like me messed with them, exiting the “?” Menu without having to go through all of it) and an example of a shooter configuring these numbers.

@Lowlight I do software for work and if you want help in app development, I’d be happy to help where I can.
 
Couple thoughts on the GB app. I watched lowlights YouTube video which explained it well. However, why are the x-factors adjustable by the user? When would I wanna adjust them? Also, I’m assuming this math only accounts for a rifle that is on the same elevation as all the targets?

I’m curious as to how this math works. Where did the x-factors come from? How were they derived?

I read through the thread posted above and it stated that the numbers came from a pool of data from many shooters. But it doesn’t describe details.
The most conversation you will get regarding that is on a couple of Franks podcasts with Mark Taylor as guest.
 
Couple thoughts on the GB app. I watched lowlights YouTube video which explained it well. However, why are the x-factors adjustable by the user? When would I wanna adjust them? Also, I’m assuming this math only accounts for a rifle that is on the same elevation as all the targets?

I’m curious as to how this math works. Where did the x-factors come from? How were they derived?

I read through the thread posted above and it stated that the numbers came from a pool of data from many shooters. But it doesn’t describe details.

I will also comment that it would be nice if the app had more useful features (resetting x-factors to default if an newb like me messed with them, exiting the “?” Menu without having to go through all of it) and an example of a shooter configuring these numbers.

@Lowlight I do software for work and if you want help in app development, I’d be happy to help where I can.
I kind of went through the same process with ballistic calculators. They want to know everything from elevation to my great grandmother’s maiden name and I couldn’t get good dope from any of the ones I tried, including the ones I paid for. I said forget that. I might as well just buy more ammo and shoot more (which is what everyone should do anyways). Then Marc Taylor created voodoo and I love that app. I get wanting to figure out how it all works with the gravity ballistics app, and you should, but as I said-it’s so simple that it will blow your mind. It’s very easy to overthink it. Basically, just take the app, create the profile for your rifle and then hit the range. If you get your hundred yard zero, then shoot out to 200, and 300 the numbers will start to settle in. If you get an anomaly then as Marc said “go back to the shooter.” Make sure your fundamentals are sound and if they are you can adjust the numbers and they will auto adjust on down the line. Also, as Makinchips208 said, listen to Frank’s podcast. There are some discussions on it
 
I covered truing BC in a post after that. I true velocity under 600 yards and true BC over 600 yards.
Nope

BC is after 800 or 900 yards, if at all.

That is what Frank taught us in class.

If you have a Kestrel with AB and you use the internal CalMV function, the distance for 6.5 CM is greater than 800 yards, and the DSF correction is way farther than 1,000 yards.
 
Nope

BC is after 800 or 900 yards, if at all.

That is what Frank taught us in class.

If you have a Kestrel with AB and you use the internal CalMV function, the distance for 6.5 CM is greater than 800 yards, and the DSF correction is way farther than 1,000 yards.
No shit! Maybe if you read what I wrote you’d have seen that’s what I said. Jesus you’re observant. Mach 1.2 is where you true BC
 
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No shit! Maybe if you read what I wrote you’d have seen that’s what I said. Jesus you’re observant. Mach 1.2 is where you true BC
You also said you true MV under 600 yards and BC over 600 yards. That was the basis for my response not your earlier statement.

Maybe you should state your thoughts more consistently.

Good luck with your shooting
 
Nope

BC is after 800 or 900 yards, if at all.

That is what Frank taught us in class.

If you have a Kestrel with AB and you use the internal CalMV function, the distance for 6.5 CM is greater than 800 yards, and the DSF correction is way farther than 1,000 yards.
Distance depends on what you’re trying to true. You true BC close to transonic which for 5.56 mk262 is close to 700 yards. For a 308 168 smk it’s closer to 800 yards. For my 6.5 it’s just past 1000 yards.

All of these are “over” 600 yards.

And I true velocity at 500 yards and it works just fine. Many do.
 
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It works for mil or moa.
That's the beauty of it.
It is based on gravities effect on the bullet,
Velocity, BC don't come into play at all.
Once you have a good 100 yd zero, you add 1 mil or moa to get close to 200.
Then take your 200 data and multiply it by 2 to get 300.
Then follow the sequence..
300 data x 1.75 = 400
400 data x1.45 =500
500 x1.45 = 600
600 x1.3 =700
700 x1.25 = 800
800 x1.24 = 900
900 x 1.22 = 1000

It's really easier than it seems on paper.
Others can explain it better than me, but it does work.
Correction; 500x1.40 = 600
Type-o I'm sure. You have a great grasp on the concept and application.
Thanks for being a great ambassador.

Taylor
 
I've been doing this for a long time now.
Not so much PRS, but match shooting and ELR the last few years. JBM before Electronic devices, and all my scopes have been MOA. It's never once cost me a point in a match ever! Again, I'm not ranging targets with my Reticle, so I get the MIL simplicity. A number is a number, mil or moa. The wind eats your lunch every time. Be it MOA or MIL, it doesn't care. I'll probably sell my one and only mil scope, 6X36 S&B and get another ATCAR in MOA.
 
Just had a range day yesterday at the Ben avery complex in Phoenix (amazing range btw, anyone in the area should check it out). I verified zero at 100 yards with an ar10 shooting Winchester white box, Hornady white tail, and Hornady 147 grain match. I averaged about 1.5 moa with the wwb and Hornady white tail. Surprisingly my groups with the 147 grain match was really bad, about 2-2.5 moa. I then took shots at 200 and 300 yards and adjusted the drop in the gravity ballistics app. I headed to the 500 meter steel target range and using the dope provided in the app, I was able to get first shot hits on 8-10” steel plates at 550 yards. For some of you, this isn’t all that great but for me using an ar10 with cheap target ammo, I was more than thrilled.

Anyways, thanks for the coaching/advice. I will try to play with other ammo and see if I can get better grouping and hit the smaller 4” targets at that distance next time.