Best practice for simple DOPE card?

[H80Hunter]

What’s the simplest way to make a dope card for hunting? Here’s what I mean. I’ll try to keep it sort of simple so someone actually replies, but it’s somewhat complex.

For my 6.5 CM, I zero at 100. Using the Hornady app I can make hits at 550 yards by putting in the exact environmentals.

However, I was planning to make a cheat sheet for some longer range food plots stands. Let’s say 400 yards max.

If I put in 0 mph wind it tells me 400 yards the dial is 8.1 MOA.

If I put in 15 mph wind from 9:00 direction it tells me to dial 9.4 MOA and 3.7 MOA wind.

If I put in a 15 mph wind from 3:00 direction it tells me to dial 7.0 MOA and 3.1 MOA.

I hope someone has stuck with me. So it seems like I should have a column for all 3 cases for direct full value side winds? It’s a pretty big difference 9.4 vs 7.0 MOA based on wind direction. Does anyone hunting over a field just use the app if you have time to figure out your dialing?

I’m just looking for a way to balance the complexity without having such a confusing card with my dials on it that in the moment I screw it up. How do you guys make a cheat sheet to easily get your holds?

 

[JollyRoger]

I use mils but you should be able to do something similar:
I have ranges/dial ups listed in 50yd increments from 200 to 750 on the side of my rifle. For my wind I just memorize the base wind for my rifle (usually 5-6mph depending on what I’m shooting). I make a quick mental adjustment from there in the event the wind is more or less, and the angle

The variance in elevation corrections based on wind data don’t make sense to me, cause it seems like a big difference for relatively close range. Someone else will likely chime in to help on that.

 

[HighUintas]

I have several cards printed and laminated. One is a density altitude chart. The other several are elevation correction for my shooting ranges in n 25yard increments. Each card is for a different density altitude. I have one for 10k, 11k, 12k, and 13k feet.

I don't currently have one for wind though. I had memorized what the wind holds in mils would be for 5mph full value. I should have added that to my cards, but I didn't. Example of 10k below

 

[BBob]

If I put in 0 mph wind it tells me 400 yards the dial is 8.1 MOA.

If I put in 15 mph wind from 9:00 direction it tells me to dial 9.4 MOA and 3.7 MOA wind.

If I put in a 15 mph wind from 3:00 direction it tells me to dial 7.0 MOA and 3.1 MOA.

Something is wrong with those numbers. There’s no way there’s that much elevation difference between those winds. There should be virtually no change at all especially at 400yds.

 

[mxgsfmdpx]

Cheat sheet card taped to the stock next to my level bubble for quick kills (I pretty much have it memorized for this season on my new 7 SAUM). I can stay within the sight picture with my right eye and glance off to both my cheat card and level bubble very easily (PRACTICE THIS you'll thank me).

Kestrel and Strelok Pro with pre-populated values for quick acquisition of numbers when I have some more time for the shot. I would recommend getting used to relying on a good anemometer with proper direction reading.

 

[ResearchinStuff]

Something is wrong with those numbers. There’s no way there’s that much elevation difference between those winds. There should be virtually no change at all especially at 400yds.

4DOF does this in BC calculator mode. not sure why. just switched from 4DOF to Shooter to get away from the problem, cause it is a problem, not reality.

OP - the simplest solution requires mils and Form's good/average/bad gun process.

 

[mxgsfmdpx]

Cheat sheet card taped to the stock next to my level bubble for quick kills (I pretty much have it memorized for this season on my new 7 SAUM). I can stay within the sight picture with my right eye and glance off to both my cheat card and level bubble very easily (PRACTICE THIS you'll thank me).

Kestrel and Strelok Pro with pre-populated values for quick acquisition of numbers when I have some more time for the shot. I would recommend getting used to relying on a good anemometer with proper direction reading.

 

[hereinaz]

Buy Applied Ballistics app.

Screenshot ballistics for temp and baro for your typical hunt and with a fixed wind like 10 mph. Email it to yourself and print it. Laminate and tape the card to your stock with some duct tape. Keep the cards and tape in your bag.

Then, in the field, dial on dope for “point blank zero” and figure out where that is in the field.

Beyond that, it’s not that hard to memorize the dope for 300-400 in 50 yard increments.

 

[H80Hunter]

Ok so I’m gathering I should look at the no wind elevation drop and then the wind doesn’t impact elevation as much as Hornady App claims?

 

[hereinaz]

There is something called aerodynamic jump, that moves a bullet up and down depending on the wind speed and angle. But I don’t think it’s that much.

The wind call and error will be compounding and it doesn’t need to be that complicated for the ranges you are talking about. If you want to learn about aerodynamic jump and why it happens it is because of “precession” of the bullet tip that traces little circles into a sort of clover shape as the bullet spins in its gyroscopically stable flight.

The bullet is never spinning perfectly around, but it has a tiny wobble, like when you touch a spinning top and it sort of wobbles in little circles around a bigger circle until it falls over or it gets back into a tighter spiral.

The precession is also why you get spin drift to the right on right twist barrels, just like a top will visibly move ever so slightly in the direction of spin with a little friction.

Another easy source is JBM ballistics online. Go build your dope charts at JBM ballistics online and print them.

I don’t mean to shy you away from getting at the details and learning, but for your purposes you don’t need to worry about much out to 400. Most new long range shooters will get more improvement by attention to their shooting position and trigger press than even the wonky Hornady app.

For what it is worth, I stopped trying to understand or work through the limitations and bugs of other software so I run Applied Ballistics, the gold standard worth its weight in Snickers bars at 40 bucks with all the features and state of the art software and modeling.

No one is doing anything like Applied Ballistics for long range shooting. They have a mobile lab and are collecting a crap ton on data, besides their own testing. The books and videos by Bryan Litz are crazy technical if you want to go there.

 

[Marshfly]

Play with the weather variables in a ballistic app for the conditions and altitude you hunt in. Find a good middle ground and make a little chart for that in Excel. Print and use packing tape to put that dude on the objective bell of your scope for easy reference. Don't forget to add a wind column.

 

[Lunchbox37]

I’ve had great experiences with the 4dof app, as long as you take the time make sure you inputs for using the Zero Angle are as accurate as possible. If using zero range it’s a bit less accurate.

@OP, For your issue with the come up values may be a discrepancy with your “rifle info setup”, meters vs yards, etc… that’s input into the calculator. I’ve helped several people by just reviewing the inputs and finding discrepancies.

For an example here’s my 4dof data for my 22” 6.5cm running 147ELDM @2641fps show me the following DOPE for 400yds @5000’ of elevation:

Zero MPH wind-
ComeUp= +1.9mil/6.54moa
Windage= -.08mil/.26moa

15mph from 9:00-
ComeUp= +2.15mil/7.4moa
Windage= -.81mil/2.77moa

15mph from 3:00-
ComeUp= +1.6mil/5.68moa
Windage= +.66mil/2.25moa

You’ll notice on my dope the 3:00 wind creates lift, this is due to the right hand spin (from a right hand twist barrel) on the projectile creating low pressure on the top of the bullet (like an airplane wing). As the wind comes into the right hand side of the bullet, it splits and the air (wind) that is being pushed under the bullet moves faster than the air being pushed over the top of the bullet. The exact opposite happens with the 9:00 wind direction. This is often referred to as “aerodynamic jump”. Edit: also known as the Magnus Effect.

I’d just double check your setup and values of using 4dof. Hope this helps.

 

[H80Hunter]

I’ve had great experiences with the 4dof app, as long as you take the time make sure you inputs for using the Zero Angle are as accurate as possible. If using zero range it’s a bit less accurate.

@OP, For your issue with the come up values may be a discrepancy with your “rifle info setup”, meters vs yards, etc… that’s input into the calculator. I’ve helped several people by just reviewing the inputs and finding discrepancies.

For an example here’s my 4dof data for my 22” 6.5cm running 147ELDM @2641fps show me the following DOPE for 400yds @5000’ of elevation:

Zero MPH wind-
ComeUp= +1.9mil/6.54moa
Windage= -.08mil/.26moa

15mph from 9:00-
ComeUp= +2.15mil/7.4moa
Windage= -.81mil/2.77moa

15mph from 3:00-
ComeUp= +1.6mil/5.68moa
Windage= +.66mil/2.25moa

You’ll notice on my dope the 3:00 wind creates lift, this is due to the right hand spin (from a right hand twist barrel) on the projectile creating low pressure on the top of the bullet (like an airplane wing). As the wind comes into the right hand side of the bullet, it splits and the air (wind) that is being pushed under the bullet moves faster than the air being pushed over the top of the bullet. The exact opposite happens with the 9:00 wind direction. This is often referred to as “aerodynamic jump”. Edit: also known as the Magnus Effect.

I’d just double check your setup and values of using 4dof. Hope this helps.

This isn’t too different from mine. If you use no wind is kind of the average. I understand the concept that the 3:00 wind is about an MOA less drop (vs no wind) and that the 9:00 wind is about an MOA more drop (vs 9:00 wind).

I’ve already got the data for elevation with basically no wind. I guess I’m just not sure what my sheet should say. I think I’m going to do a column for all three cases. The 3:00, 9:00 and zero wind.

That seemed a little complicated but seems like it may be necessary.

 

[hereinaz]

I’ve had great experiences with the 4dof app, as long as you take the time make sure you inputs for using the Zero Angle are as accurate as possible. If using zero range it’s a bit less accurate.

@OP, For your issue with the come up values may be a discrepancy with your “rifle info setup”, meters vs yards, etc… that’s input into the calculator. I’ve helped several people by just reviewing the inputs and finding discrepancies.

For an example here’s my 4dof data for my 22” 6.5cm running 147ELDM @2641fps show me the following DOPE for 400yds @5000’ of elevation:

Zero MPH wind-
ComeUp= +1.9mil/6.54moa
Windage= -.08mil/.26moa

15mph from 9:00-
ComeUp= +2.15mil/7.4moa
Windage= -.81mil/2.77moa

15mph from 3:00-
ComeUp= +1.6mil/5.68moa
Windage= +.66mil/2.25moa

You’ll notice on my dope the 3:00 wind creates lift, this is due to the right hand spin (from a right hand twist barrel) on the projectile creating low pressure on the top of the bullet (like an airplane wing). As the wind comes into the right hand side of the bullet, it splits and the air (wind) that is being pushed under the bullet moves faster than the air being pushed over the top of the bullet. The exact opposite happens with the 9:00 wind direction. This is often referred to as “aerodynamic jump”. Edit: also known as the Magnus Effect.

I’d just double check your setup and values of using 4dof. Hope this helps.

Do what he says to double check Hornady app. I know lots of people use it. I don’t. Seems like people have more trouble with it from a user side, cause it is different than others.

Ballistic need alert, stop reading unless you care about details…

AJ is not “lift” technically, but it is not the first time that I have heard people use that example to explain it.

It’s like touching a spinning top. If you touch it on the right side, the top will travel to the left and “up” because the tip is spinning in a small spiral on the ground and every little circle it travels a little bit left and up as the gyroscopic forces stabilize it until it stands up straight again and stops moving.

If you touch a spinning top on the left side, it will travel to the right and down as it spins its little circles and balances itself and stands up.

Wind deflection is knocking the bullet off balance a little and as it gyroscopically stabilizes itself like the top, it wobbles a little and moves in “two directions” up and sideways.

The sideways effect of wind is always more, and the vertical is smaller only caused by the gyroscopic forces that stabilize the bullet.

One way to conceptualize it is that the spinning bullet climbs vertically when the spin is into wind and it falls vertically when the spin is with the wind.

 

[ResearchinStuff]

4dof produces different solutions depending on if you're using the bc calculator or the 4dof side. Identical rifle setups, 140 eldm, one calculated using the 4dof engine, the other with g1 bc. You can easily see the bc calculator overcalulating the effect of aerodynamic jump.

 

[hereinaz]

This isn’t too different from mine. If you use no wind is kind of the average. I understand the concept that the 3:00 wind is about an MOA less drop (vs no wind) and that the 9:00 wind is about an MOA more drop (vs 9:00 wind).

I’ve already got the data for elevation with basically no wind. I guess I’m just not sure what my sheet should say. I think I’m going to do a column for all three cases. The 3:00, 9:00 and zero wind.

That seemed a little complicated but seems like it may be necessary.

No one I know runs different elevation for wind direction. Don’t over complicate it.

If it matters to you to figure it out, then go test it on your rifle to get real data. Calculators are still just models to predict, and they aren’t perfect either.

I decided to learn stuff like this as a rifleman on the gun, not with a calculator nerd like I really am.

Learning the science is good.

Just don’t get caught up in this stuff, cause you gotta learn a whole lot more to even begin to figure out how to tell why a calculator is being wacky.

As a guy who nerded out too much, I recommend you learn to fudge up or down based on gut feel just like you do wind holds. If it is actually about 1 moa, each way for a 10 mph wind depending on direction just factor it in and dial up or down half moa. You don’t need an overly complex sheet of paper.

Inside 400 yards, you aren’t missing because of aerodynamic jump.

 

[H80Hunter]

Makes sense I’m probably not taking a 400 yard shot in a crosswind in Wisconsin anyway. Just trying to understand as the 2 MOA elevation difference seems weird to me.

I have confirmed elevation with the gun with little wind just wasn’t sure how detailed I should be for a real world hunting scenario but I think I got it.

 

[hereinaz]

It’s a great question by the way.

A full value 20 mph wind is 3” of vertical change at 400 yards for a 6.5 creed of mine. In my opinion, that is something that can be fudged a little up or down as part of a wind hold.

 

[wind gypsy]

I think i saw someone post here a generic 9 MPH full value wind is 0.1 mil aerodynamic jump. That seems like a reasonable way to look at it, for a MOA scope that would translate to a 6 MPH full value wind = .25 MOA up or down.

That + MPH wind brackets + just not shooting at animals that far away seems like a streamlined process for hunting shots most of us have any business taking.

Seems like 4DOF is getting lots of people funky data with AJ if not using their ballistic curves and doesn't have an option for Density altitude? I'd skip it because of that.

 

[hereinaz]

I think i saw someone post here a generic 9 MPH full value wind is 0.1 mil aerodynamic jump. That seems like a reasonable way to look at it, for a MOA scope that would translate to a 6 MPH full value wind = .25 MOA up or down.

That + MPH wind brackets + just not shooting at animals that far away seems like a streamlined process for hunting shots most of us have any business taking.

Seems like 4DOF is getting lots of people funky data with AJ if not using their ballistic curves and doesn't have an option for Density altitude? I'd skip it because of that.

I think you have the right idea. Inside 450 to 550 yards depending on MV, many things can be fudged with a simple rule like that. I don't know whether it will be practically a "linear" adjustment adding a value for the range or whether it will be "algebraic" to multiply.

I jump into a calculator to figure that out. Usually, when I want to run through something like that, I typically go online to JBM online so that I can open one window and then run different scenarios and print the data for each scenario on paper or as a PDF file to compare.

For instance, I follow the "wind number" for my guns. That involves figuring out what value wind equals .1 mil for every hundred yards, and I can usually find a number that works from 300 to 1000. My hunting rifles tend to be about 7 mph, so a 7 mph wind is .4 at 400, .6 at 600, etc.

I am sure that you could figure out a simple rule like that for AJ as well. I have just never done it.

If you do some calculations, I'd be curious to see them.