Shorter range data not lining up with mile data

[Ryken93]

Hey, so I’m a little confused with some new data. I’m using a 26” .338LM, Hornady ELD match 285gr, with an average velocity of 2821 FPS (Caldwell chronograph, so maybe it’s not accurate)

but my issue is….
For starters my reliable data is, I have impacts from 700 - 1200 yards and the MIL adjustments can all make sense and follow a dope chart based on similar muzzle velocities, and for your info, specifically I hit 1200 at about 8.5 mils all day…. but, I just hit a mile yesterday (twice) at 14.2 mils, and all my misses were high… if I use the same calculations I’ve made all my impacts at 1200 yards and under my chart says it should be about 15.2 mils… I can not figure out how it’s a full MIL off.
How can the data not be anywhere near consistent?

sorry if that’s confusing… hard to explain

tyia

 

[THEIS]

Hi,

What "Chart" are you using?
Where did this "Chart" come from?

Sincerely,
Theis

 

[Precision Underground]

The further out you go, more parameters and the accuracy of those parameters will matter. Also, a lot of people hit a 20" tall plate at 1000 and think their dope is correct. You need a waterline on the plate to see exactly where you hit on the plate. If you hit at the top edge and then dialed out to a mile with that data set you will prob be high. Your data is not correct at 500, 700, 1000 until you're hitting the vertical level that you're aiming at rather than just hitting the plate that you're aiming at. This can be a little difficult to work out if you cant drive to or put a water line on the target and identify exactly where your impact is.

 

[Ryken93]

The further out you go, more parameters and the accuracy of those parameters will matter. Also, a lot of people hit a 20" tall plate at 1000 and think their dope is correct. You need a waterline on the plate to see exactly where you hit on the plate. If you hit at the top edge and then dialed out to a mile with that data set you will prob be high. Your data is not correct at 500, 700, 1000 until you're hitting the vertical level that you're aiming at rather than just hitting the plate that you're aiming at. This can be a little difficult to work out if you cant drive to or put a water line on the target and identify exactly where your impact is.

This is probably what my problem is

 

[Ryken93]

The further out you go, more parameters and the accuracy of those parameters will matter. Also, a lot of people hit a 20" tall plate at 1000 and think their dope is correct. You need a waterline on the plate to see exactly where you hit on the plate. If you hit at the top edge and then dialed out to a mile with that data set you will prob be high. Your data is not correct at 500, 700, 1000 until you're hitting the vertical level that you're aiming at rather than just hitting the plate that you're aiming at. This can be a little difficult to work out if you cant drive to or put a water line on the target and identify exactly where your impact is.

 

[Ryken93]

Okay, I’m really stumped now… I went out and got three hits in a row at 13.5 mils… even less mils today and the weather was worse, should of been hitting lower than last time…
So the only thing I can think is I wonder if I’m having Mirage issues…
I’m using the 35x NF scope, and I do believe the visible mirage was worse today… and I wonder if I’m getting significant poi difference from mirage at 35x?

 

[Precision Underground]

Okay, I’m really stumped now… I went out and got three hits in a row at 13.5 mils… even less mils today and the weather was worse, should of been hitting lower than last time…
So the only thing I can think is I wonder if I’m having Mirage issues…
I’m using the 35x NF scope, and I do believe the visible mirage was worse today… and I wonder if I’m getting significant poi difference from mirage at 35x?

Again, hits don’t mean much on large plates when it comes to dope accuracy. Where did you hit? What chart are you looking at? If it’s a generic chart it’s not going to do you any good past 800 yards unless you document and adjust for exactly where on the plate you’re hitting. Also, if your shooting groups at 100 that are 1”, remember that puts your spread (ignoring wind and environmental factors) at around 17”. Even if you have 1/2” groups and exact dope documented you’ll still be dealing with environmental factors that can change your numbers at a mile.

My advice would be to start at 100 or 200 and see how small you can get your groups while you get an exact zero. Then get a good ballistics app and load all of your data in. Move out to 4-6-800 and document/adjust your app until your dope aligns as good as possible on exact vertical aiming points. Then you can see how 1 mile lines up.

 

[Ryken93]

Again, hits don’t mean much on large plates when it comes to dope accuracy. Where did you hit? What chart are you looking at? If it’s a generic chart it’s not going to do you any good past 800 yards unless you document and adjust for exactly where on the plate you’re hitting. Also, if your shooting groups at 100 that are 1”, remember that puts your spread (ignoring wind and environmental factors) at around 17”. Even if you have 1/2” groups and exact dope documented you’ll still be dealing with environmental factors that can change your numbers at a mile.

My advice would be to start at 100 or 200 and see how small you can get your groups while you get an exact zero. Then get a good ballistics app and load all of your data in. Move out to 4-6-800 and document/adjust your app until your dope aligns as good as possible on exact vertical aiming points. Then you can see how 1 mile lines up.

Yeah, I didn’t get to a mile without going there first man… I’m not using internet charts… I’m calculating on my own taking into consideration literally everything… corliolis, spin drift, pressure, temp, altitude, slope, cant, MV, coefficient… etc….
I’m having a more complicated issue man….

 

[hafejd30]

Every day the dope can change. Based on weather, wind, sun vs clouds, temp of ammo/rifle etc etc etc etc etc

Just because your hitting accurately at 800 yards today. Doesn’t mean in 3-4 hours from now that data will be just as accurate

Conditions change as does the temp of your equipment.

Even your BC being incorrect in your ballistic app, or whatever you use, will cause rounds to be off

I’ve personally shot 1000 fclass matches where my zero at 1,000 yards changed over 1 MOA in the same day. Crisp/cool cloud covered morning vs sun high in the sky, variable wind, heavy mirage afternoon. Same target, same gun, same ammo

Welcome to the world of long range shooting. Where just when you think you’ve figured it all out you learn something new

 

[Ryken93]

Yes I know…. I track all my weather and BCs and MVs and I’m trying to figure out why the data isn’t lining up… yes I get MIL differences from weather and MVs and BCs that make sense.
but I’m telling you my data is not making sense. I’m trying to figure it out.
Are you telling me you’re getting 1 MOA different and you have no idea why? And you just move back to 200 yards and start over?

cuz you’re assuming I don’t understand how to calc drops… I do… and I’m telling you the data isn’t making sense….

So now, I’m asking people, does anyone have info about mirages for me… am I getting huge unpredictable poi differences because of mirage differences?

 

[hafejd30]

Yes I know…. I track all my weather and BCs and MVs and I’m trying to figure out why the data isn’t lining up… yes I get MIL differences from weather and MVs and BCs that make sense.
but I’m telling you my data is not making sense. I’m trying to figure it out.
Are you telling me you’re getting 1 MOA different and you have no idea why? And you just move back to 200 yards and start over?

cuz you’re assuming I don’t understand how to calc drops… I do… and I’m telling you the data isn’t making sense….

So now, I’m asking people, does anyone have info about mirages for me… am I getting huge unpredictable poi differences because of mirage differences?

I’m telling you there’s many factors that come into play. Not that there’s no idea why. The added heat, mirage, even winds increased from the 12 or 6 position (especially with hills/valleys) can change the drop. Mirage can cause more “lift” off the surface of the earth. The sunlight refracting can change the zero appearance of the target to the shooter

 

[Ryken93]

I’m telling you there’s many factors that come into play. Not that there’s no idea why. The added heat, mirage, even winds increased from the 12 or 6 position (especially with hills/valleys) can change the drop. Mirage can cause more “lift” off the surface of the earth. The sunlight refracting can change the zero appearance of the target to the shooter

Well I suppose this answers my question, and it is the stuff that I’m trying to figure out… the weather and ammo data isn’t making sense… for me to be impacting at 13.5 mils in my weather conditions I would of needed to be cranking 130 FPS more…
2950 FPS…. So there’s some other variables at play I haven’t learned yet… I’m thinking it’s mirage poi.

 

[hafejd30]

Well I suppose this answers my question, and it is the stuff that I’m trying to figure out… the weather and ammo data isn’t making sense… for me to be impacting at 13.5 mils in my weather conditions I would of needed to be cranking 130 FPS more…
2950 FPS…. So there’s some other variables at play I haven’t learned yet… I’m thinking it’s mirage poi.

I’m seriously not trying to be a dick about my answers to your questions

Just trying to point out that even with a top tier ballistic app, kestrel weather meter and everything accounted for the drop may be off by a bit. Especially at a mile

ELR is a different animal. I’ve sat next to some of the top shooters in the country (Brian Litz) etc and seen them throw a 7 or 8 on a 1,000 yard target.

Conditions change and even allowing your ammo to sit in the chamber longer than the previous round can change the point of impact

 

[Ryken93]

Well I suppose this answers my question, and it is the stuff that I’m trying to figure out… the weather and ammo data isn’t making sense… for me to be impacting at 13.5 mils in my weather conditions I would of needed to be cranking 130 FPS more…
2950 FPS…. So there’s some other variables at play I haven’t learned yet… I’m thinking it’s mirage poi.

 

[Blaiz1]

Okay, I’m really stumped now… I went out and got three hits in a row at 13.5 mils… even less mils today and the weather was worse, should of been hitting lower than last time…
So the only thing I can think is I wonder if I’m having Mirage issues…
I’m using the 35x NF scope, and I do believe the visible mirage was worse today… and I wonder if I’m getting significant poi difference from mirage at 35x?

have you trued your rounds at trans sonic

 

[THEIS]

Hi,

Post up a few things:

1. The "Charts".
2. What program are you using to create the charts?
3. Post the actual individual pages of inputs you are plugging in to create the "charts".

Also please advise of the following:
1. What is your shooting experience level?
2. What is the shooting conditions in regards to terrain?
3. Are you really as good as you may think you are in regards to detecting, reading and calculating for not only multiple wind zones but different microenvironments?
4. And when you say "average" velocity.....what is the low and high velocity?
5. Are you tracking which velocity reading impacts where on the target?

Sincerely,
Theis

 

[b6graham]

Shooting at 35x
Has elevation changes from day to day
Makes his own 'charts' with mostly irrelevant data

Ignores mirage comments

Sounds pretty simple to me

 

[Ryken93]

Yeah, I know

I’m seriously not trying to be a dick about my answers to your questions

Just trying to point out that even with a top tier ballistic app, kestrel weather meter and everything accounted for the drop may be off by a bit. Especially at a mile

ELR is a different animal. I’ve sat next to some of the top shooters in the country (Brian Litz) etc and seen them throw a 7 or 8 on a 1,000 yard target.

Conditions change and even allowing your ammo to sit in the chamber longer than the previous round can change the point of impact

Shooting at 35x
Has elevation changes from day to day
Makes his own 'charts' with mostly irrelevant data

Ignores mirage comments

Sounds pretty simple to me

I have all the apps, mostly I use TRASOL and StrelokPro.

I think the mirage might be my problem as you’ve stated, mirage effects elevation day to day, thank you that’s helpful. Does anyone know how to calculate elevation changes for mirage? Or do you just have to dial down the magnification.


This is my data as someone asked previously

Desert Tech srs A2 26”
338 LM Hornady ELD Match 285gr
Scope height 2.63”
Zero 100

zero weather 75*
23.02
26%

MV: 2802 low
2830 high

BC:.417 @2512
.409@2232
.400 1953


Yards 1762
Slope 0
Cant
Wind is sub 3 mph so I don’t think it matters for my elevation problem
DA 9830 temp 77

40.7 lat


Depending on the app, it’s around 15 mils.

I made 3 impacts in a row at 13.5 mils yesterday.
So sifting through people’s comments, we’ve maybe established I’m having mirage issues

 

[Ryken93]

It would be fantastic if someone calc’d these numbers and showed me why I’m wrong

 

[b6graham]

If you could calculate mirage with a formula you'd be a god

Id back out to 12-20x and see what happens

 

[Ryken93]

If you could calculate mirage with a formula you'd be a god

Id back out to 12-20x and see what happens

Haha, damn, well two days on this thread and I guess that’s the answer…
Someone make a mirage app!

 

[b6graham]

Haha, damn, well two days on this thread and I guess that’s the answer…
Someone make a mirage app!

@THEIS and his secret squirrel army probably are

 

[Ryken93]

@THEIS and his secret squirrel army probably are

@THEIS let me beta test

 

[Ryken93]

Yeah, I know


I have all the apps, mostly I use TRASOL and StrelokPro.

I think the mirage might be my problem as you’ve stated, mirage effects elevation day to day, thank you that’s helpful. Does anyone know how to calculate elevation changes for mirage? Or do you just have to dial down the magnification.


This is my data as someone asked previously

Desert Tech srs A2 26”
338 LM Hornady ELD Match 285gr
Scope height 2.63”
Zero 100

zero weather 75*
23.02
26%

MV: 2802 low
2830 high

BC:.417 @2512
.409@2232
.400 1953


Yards 1762
Slope 0
Cant
Wind is sub 3 mph so I don’t think it matters for my elevation problem
DA 9830 temp 77

40.7 lat


Depending on the app, it’s around 15 mils.

I made 3 impacts in a row at 13.5 mils yesterday.
So sifting through people’s comments, we’ve maybe established I’m having mirage issues

 

[Mike Casselton]

OP,
go outside and look down a couple miles of blacktop in the middle of the day.

Watch the cars crossing and coming/going up and down the road.

Take a look at a road sign and notice how it moves and where that movement stops and pauses before resuming movement.


There's no mathematical way to predict or calculate it.

There are ways to WATCH the mirage and find out where the target actually is vs where it appears to be....

Get off the computer and go outside.
Hell, take a spotting scope or binoculars and look

 

[Ryken93]

I don’t know why people talk like this on here “get off the computer”…. If you’re info is so valuable, I would of never learned it without a computer…

 

[Mike Casselton]

Don't get butthurt over it.
You can only learn so much by reading.
The rest has to be OJT.

You have two threads going with different titles and you're searching for the same answer.

Go back through the threads and read what people have answered and specifically, what information people are asking you to provide so our help is more focused.


If you're truly here to learn, then set aside your feelings and pay attention.

 

[Ryken93]

I shoot everyday and I live and work on a ranch… outside time is not an issue

 

[Mike Casselton]

I shoot everyday and I live and work on a ranch… outside time is not an issue

So then use that outside time to educate yourself.

Just being outside doesn't count.

Since a one or two mile stretch of blacktop isn't really in your cards, then prone in a prairie dog town can teach you about mirage.

You still have to use that time wisely.
Set up small targets and watch them through your optics.

Do you have a spotting scope?
If not, set your rifle up on a target with the crosshairs centered. Get your rifle at the height where you can just see over the hood of your truck.

Watch the target.

Drive your truck up within a foot or so of your rifle. Make sure the hood is between you and the target.
Look at the target.
It should be moving around and flicking and fro.

That's what mirage does to your image and how it affects percieved location.

Play with the zoom and see where the movement is minimized.

It doesn't make it go away, it just changes your ability to see it.

I learned long ago to watch mirage and then learned to shoot through it without zooming out on the scope

 

[Skg_Mre_Lght]

The hardest part of learning for a human being is to squash their ego, and admit they may not know something.

The answers have been given to you, but the only way you learn how different environmental factors affect your ability to precisely put rounds on target is to shoot in them. Couple that with a solid knowledge of what is happening to your bullet, and why, and you will get pretty good at your chosen hobby.

We see it all of the time when shooting competitions. People are convinced they are better than they are, and many give up when reality hits them hard. Don't do that. I suggest taking a course, or two from a reputable instructor, and start from there.

Shooting everyday means nothing if you don't understand why something is happening.

 

[jasent]

One thing about the Caldwell chrono. It’s accuracy it +/- 2%. And that’s if it’s lined up square with bullet path. Few degrees out of square that can be +/-3-5%. That adds up. Also wind from right to left will push bullet left and up

 

[MarcC11B]

You sure you’re not having a scope or mount issue? Do you start your shooting session with checking zero?