Data Cards and Angled Shots

[Jackomason]

I'm planning out my elk hunt thats coming up in the fall. The two places I'm least confident is shooting in a new environment and angled shots. I live at the base of a mountain range so I can go up an play around a little but usually shoot on the flats.

1. If you true your data with one set of atmospherics does it true your data across all atmospheric conditions given that you input them into your software.
E.g.. I shoot with a BP of 22.3 and my data is trued for it. Will that translate to my elk hunt if I plug in my new BP at 11k feet? Or do I have to true my data again at that elevation? (I can if need be)

2. I have a sig kilo 2000, you mentioned that doing the long math ends up being more accurate then trusting the range finder to do it. How big of an error factor were you talking? Will that alone cause me to miss my 15" kill zone at 800 - 1000 yards? Obviously an angle dependant question but I'll leave that open.

3. I've read people talk about shooting through multiple Beriometric zones when shooting in the mountains, how do you calculate the effect that will have on trajectory?

Thanks again for the pod cast, I think I'm going to dumb down my reloading and throw the stress out the window! Who would have thought frank could relieve stress being the social grenade that he is... keep it up!

 

[Deleted member 113831]

I multiply the cosine of the angle to the dope, rather than the distance. It is a bit more accurate, but at angles of 20 degrees and less the difference isn't worth mentioning at those ranges.

Example: 6.5 Creed, 140 ELD, @ 2750 fps, at 1000 yards, 20.0Hg where you were talking about hunting, 1.8 inch scope height.

1000 yds straight line dope = 6.88 mils (23.6 moa)

20 degree angle cosign (.937) multiplied to distance = 6.22 mils (21.38 moa), applied to dope = 6.44 mils (22.14 moa), actual = 6.38 mils (21.9 moa)

40 degree angle cosign (.757) multiplied to distance = 4.47 mils (15.36 moa), applied to dope = 5.20 mils (17.87 moa), actual = 4.93 mils (16.94 moa)

 

[Jackomason]

That makes sense, so the "actual" you have posted is real world? Cause .3 at 1000 is 10.8 inches from center, however I can't imagine shooting a 40° angle that far in these mountains. Guess I've gotta get an angle cosine indicator. Thanks for the explanation!

 

[Deleted member 113831]

.3 mils at 1000 is 10.8 inches

.3 moa at 1000 is 3.14 inches

Values listed as actual were calculated with a ballistics program.

 

[Deleted member 113831]

That makes sense, so the "actual" you have posted is real world? Cause .3 at 1000 is 10.8 inches from center, however I can't imagine shooting a 40° angle that far in these mountains. Guess I've gotta get an angle cosine indicator. Thanks for the explanation!

The way to do this accurately, so you don't have to depend on a ballistic program in the field, is pretty simple. Write down your 1000 yd straight and level dope. Then, use your ballistics program to calculate your actual dope for the angle you want to know. Take the angle dope spit out by the computer, and divide it by your straight and level dope. This will give you a ballistically adjusted cosine.

I'll use the 40 degree example above:
40 degree actual dope at 1000 yards = 4.93 mils.
Straight line dope at 1000 yards = 6.88 mils.
Dividing 4.93 by 6.88 = .716
Checking your work.....6.88 x .716 = 4.926, plenty close enough.

This is your ballistically adjusted cosine. You can do this for as many angle increments as you wish and keep a short list of them handy. This way, you don't have to depend on a device, and your dope will be correct for your rifle and area of operations.

 

[Jackomason]

Awesome, would you suggest having the 'answers' printed out? Maybe every 10° up to 40° for every 100 yard mark on a pretty standard or normal set of atmospherics for my area?

I could see using that then fine tuning by comparing it to the data pages set up for where I'm hunting. I'll probably bring 3 or 4 different pages anyway. But this has got me thinking and I really appreciate it.

I'm going to play with JBM a little and see if I can come up with a chart then see how easy it is to work with across a variety of environmentals. I guess I could always just bring a pocket calculator with me but I'd like to have a quick/dependable option.

Thanks again, if you have any ideas on how you or other people bring and apply these numbers in the field, I'd like to know!

 

[Deleted member 113831]

Awesome, would you suggest having the 'answers' printed out? Maybe every 10° up to 40° for every 100 yard mark on a pretty standard or normal set of atmospherics for my area?

I could see using that then fine tuning by comparing it to the data pages set up for where I'm hunting. I'll probably bring 3 or 4 different pages anyway. But this has got me thinking and I really appreciate it.

I'm going to play with JBM a little and see if I can come up with a chart then see how easy it is to work with across a variety of environmentals. I guess I could always just bring a pocket calculator with me but I'd like to have a quick/dependable option.

Thanks again, if you have any ideas on how you or other people bring and apply these numbers in the field, I'd like to know!

I'm a knuckle dragger. I write stuff on tape and stick it to my stock. The cosines don't change that much with range, just angle. A data card is never a bad thing to have. In the field simpler is better. A small rite in the rain note pad in an inside pocket is pretty bomb proof. I carry a small solar calculator with me always. It makes life easy and batteries aren't a concern. If it is light enough to worry about any of this, it will be light enough to use the calculator.

The environmentals for a given area won't vary enough to make a difference. You would only need to recalculate for an area a few thousand feet different in elevation.

 

[Jackomason]

I just ran it through 4dof, looks like if I want to go the route of a data card is have to write out every 5° or so. I may just do the cosine taped inside the calculator cover. But your right the cosine is consistent and the Dope is effected across the board pretty evenly and predictably by altitude/BP change (if it's - .1th @ 0° then it's still -.1th @ 40°). I live at the base of the mountain at 7050ft and tree line is at 11000ft, I'm planning to hike next weekend and hopefully I can gather some good data. I can't help but feel the need to test this in the real world. I did write up a chart that's very hypothetical but it is enlightening and interesting to see how these variables interact with one another.

 

[Deleted member 113831]

I just ran it through 4dof, looks like if I want to go the route of a data card is have to write out every 5° or so. I may just do the cosine taped inside the calculator cover. But your right the cosine is consistent and the Dope is effected across the board pretty evenly and predictably by altitude/BP change (if it's - .1th @ 0° then it's still -.1th @ 40°). I live at the base of the mountain at 7050ft and tree line is at 11000ft, I'm planning to hike next weekend and hopefully I can gather some good data. I can't help but feel the need to test this in the real world. I did write up a chart that's very hypothetical but it is enlightening and interesting to see how these variables interact with one another.

I am glad I could help, even if just a bit. Good shooting!

 

[Diver160651]

Just to add, if you know the rough degrees to cosign - you can quick rough it out when you find that steep shot and need to get on it quickly. Most of us are remarkable good and estimating 10°/20°/30°/40°. if your not, it is super easy to practice at home.

So if 10° is roughly 1.5% less drop, or a cosign of .985, 20° =.94, 30° = .866, 40° =.766 - then if used with rough head math, you'll be close in most cases to get a valuable GD.

When you have time for a calculator and a terrain map, sure pop out the calculator.. or toil through pages in your data book.

But.. remember if the wind is blowing the gravity distance is not what you use for that call.. Same issue with a range finder with angle compensation.

 

[Lowlight]

Also, do not use the corrected distance in a calculator they cannot handle it

You have to use the straight line distance and then include the angle vs correcting it.

The Cosine is used with the straight line Dope vs using the distance. So keep the distance straight line and correct the drop solution via the cosine.

 

[Diver160651]

Also, do not use the corrected distance in a calculator they cannot handle it

You have to use the straight line distance and then include the angle vs correcting it.

The Cosine is used with the straight line Dope vs using the distance. So keep the distance straight line and correct the drop solution via the cosine.

FYI I was talking about a calculator like an HP to work cosign.. Not a ballistics solver with AOF fields.

 

[Lowlight]

I get that, you were all good, just timing

 

[Deleted member 113831]

The idea though, is to do this stuff as ahead of time as you can. The things you can do at home, do at home.

When you get to a spot, immediately start making a mental range card, if not an actual range card.

Look at your farthest possible shot, your steepest angle, major landmarks and look for any dead space. Dead space is any area that contains enough unobservable area behind it that an animal might move through or hide in it. So when the elk steps out from behind that hill, or boulder, or clump of bushes, you already know the range, the angle, and the dope.

 

[Jackomason]

Also, do not use the corrected distance in a calculator they cannot handle it

You have to use the straight line distance and then include the angle vs correcting it.

The Cosine is used with the straight line Dope vs using the distance. So keep the distance straight line and correct the drop solution via the cosine.

Yeah, I'm really not sure how well the 4DOF app handles angled shots maybe I did something completely wrong but I used some confirmed dope and played with the angle. At 40° and 1000 yards it takes my straight line 6.05 mills and spits out 2.56 mils. That's roughly 42%, No where near skookums 72%.

JBM gave me 5.9 mils to 4.3 mils and that would be 71%. This being said I really haven't spent enough time with 4DoF

 

[Deleted member 113831]

I would trust JBM. It has never let me down. I have never been able to get 4DOF to work well. Maybe it's user error like you said, the user interface isn't the most intuitive.

I use Strelok Pro on my phone. I have been developing my own custom drag curve using Strelok's multi-BC function. It was dead on at 2,384 yards with my 338 Allen.

 

[LastShot300]

Don't get the idea of using the cosine plus a calculator in the field. I just print out from CB my angled field firing solution and done. Less than 2 secs and 100% accurate and no need to err doing the cosine (which is the wrong way) and batteries...and this in case I don't have time to pull out my phone with the solver. My 2 cents.

 

[Deleted member 113831]

Don't get the idea of using the cosine plus a calculator in the field. I just print out from CB my angled field firing solution and done. Less than 2 secs and 100% accurate and no need to err doing the cosine (which is the wrong way) and batteries...and this in case I don't have time to pull out my phone with the solver. My 2 cents.

Ballistically adjusted cosines are accurate. If you don't know what that is, refer to post #5.
The idea is to get away from relying on an app in the field, where shit tends to go sideways time to time.
Printed dope is the most durable, but you may need to extrapolate between graduations.
A simple list of cosines and a calculator will give you the exact solution you need.
If you aren't a complete ignoramus, you might even be able to figure it in your head.
This is the way it was done for a few decades before the ballistic app was invented.

My 2 cents.

 

[LastShot300]

Ballistically adjusted cosigns are accurate. If you don't know what that is, refer to post #5.
The idea is to get away from relying on an app in the field, where shit tends to go sideways time to time.
Printed dope is the most durable, but you may need to extrapolate between graduations.
A simple list of cosigns and a calculator will give you the exact solution you need.
If you aren't a complete ignoramus, you might even be able to figure it in your head.
This is the way it was done for a few decades before the ballistic app was invented.

My 2 cents.

Don't worry, I know perfectly what the Rifleman Rule is, and as you may know its limitations are very well known and I don't like approximate solutions for my LR work, when there are much better options, and still a calculator is needed, in short I don't see where the advantage lies. I have studied this in full detail and all I need is a printout from Coldbore and no guessing plus no need to deal with batteries if that this is all about, otherwise I don't see what the whole point is.

 

[Deleted member 113831]

You didn't read post #5.

 

[LastShot300]

You didn't read post #5.

Actually I did. I take you like to carry to the field a calculator, pen and paper and still getting an approximation. If that's your case, fine by me. I rather take a printout of a 100% accurate solution, to any range and for any angle.

 

[Deleted member 113831]

Actually I did. I take you like to carry to the field a calculator, pen and paper and still getting an approximation. If that's your case, fine by me. I rather take a printout of a 100% accurate solution, to any range and for any angle.

I will attempt to spell this out for you once more....

Step 1) Take your VERFIED STRAIGHT LINE DOPE
Step 2) Calculate your angle dope ON A BALLISTIC CALCULATOR
Step 3) Divide your CALCULATED ANGLE DOPE by your VERIFIED STRAIGHT LINE DOPE

The result is your BALLISTICALLY CORRECT cosign. This is not an approximation. This is reverse engineering the cosign that your BALLISTIC CALCULATOR determined was correct for this angle.

You obviously don't read too well. The prospect of carrying some type of chart or data book was discussed as a possibility in several posts.
You obviously don't reason too well, because you obviously failed to pick up the salient points made in post #5 that I have reiterated here for you.
You seem to be OK with paper.
You seem to be OK with your ballistic calculator.
Yet, you seem to have a strange aversion to carrying a simple solar calcuator and doing your own math, using inputs from your own BALLISTIC FUCKING CALCULATOR!

 

[LastShot300]

I will attempt to spell this out for you once more....

Step 1) Take your VERFIED STRAIGHT LINE DOPE
Step 2) Calculate your angle dope ON A BALLISTIC CALCULATOR
Step 3) Divide your CALCULATED ANGLE DOPE by your VERIFIED STRAIGHT LINE DOPE

The result is your BALLISTICALLY CORRECT cosign. This is not an approximation. This is reverse engineering the cosign that your BALLISTIC CALCULATOR determined was correct for this angle.

You obviously don't read too well. The prospect of carrying some type of chart or data book was discussed as a possibility in several posts.
You obviously don't reason too well, because you obviously failed to pick up the salient points made in post #5 that I have reiterated here for you.
You seem to be OK with paper.
You seem to be OK with your ballistic calculator.
Yet, you seem to have a strange aversion to carrying a simple solar calcuator and doing your own math, using inputs from your own BALLISTIC FUCKING CALCULATOR!

What part of what I've written so far, you don't understand? It's clear you don't know enough about real LONG RANGE ballistics. You can explain this BS ten times and will still smell like BS. Please spare my time, no need for cheap lectures on what angled shooting really is. You need to understand that your formula is still an approximation. For instance, how does it differentiate between uphill and downhill shots? How does your formula compensate for air density changes?

So, for the sake of proper information, stop saying your "formula" is NOT an approximation.

BTW, what in hell is a COSIGN?

 

[Deleted member 113831]

What part of what I've written so far, you don't understand? It's clear you don't know enough about real LONG RANGE ballistics. You can explain this BS ten times and will still smell like BS. Please spare my time, no need for cheap lectures on what angled shooting really is. You need to understand that your formula is still an approximation. For instance, how does it differentiate between uphill and downhill shots? How does your formula compensate for air density changes?

So, for the sake of proper information, stop saying your "formula" is NOT an approximation.

BTW, what in hell is a COSIGN?

Yeah, it's "cosine", so what....

I should have known by the way you were so overt in mentioning ColdBore in your posts, that you fancied yourself some sort of ballistics intelligentsia.
I have been long range shooting long enough to know, not only WHAT is important in making the shot, but WHEN it is important.
It's also clear that you haven't spent a lot of time shooting at shit that doesn't stand still.

This thread was started by a guy that wants to go hunting, and you are busting balls over shit that amounts to about 1 click....at 1000 yards....at a 40 degree angle, no less.

 

[LastShot300]

Yeah, it's "cosine", so what....

I should have known by the way you were so overt in mentioning ColdBore in your posts, that you fancied yourself some sort of ballistics intelligentsia.
I have been long range shooting long enough to know, not only WHAT is important in making the shot, but WHEN it is important.
It's also clear that you haven't spent a lot of time shooting at shit that doesn't stand still.

This thread was started by a guy that wants to go hunting, and you are busting balls over shit that amounts to about 1 click....at 1000 yards....at a 40 degree angle, no less.

Coldbore, JBM, AB, you name it smartass...just happens I use CB, so what? If your advice is to carry a calculator, a pen and paper, it's pretty much clear that the last time you did REAL LR work in the field was in your wet dreams.

You nailed it...the OP was asking about HUNTING and you sugested using a "field kit" to replace a 100% accurate printout?

Keep posting BS, I'm done with you pal.

 

[Deleted member 113831]

Keeping a print out, data book, data card, tape on the stock...that was all covered in posts #6 & #7.

Solar calculators aren't just for calculating angle dope, they are for doing wind math, especially when you have multiple wind zones to deal with. When you spend days in the field without electricity, they tend to come in handy.

Unless your coldbore program has inputs for light effects, it isn't the 100% accurate that you think it is.

The rest is just picking nits, 'cause the difference is just too small to matter in an actual field environment.

 

[Jackomason]

Yes, it was discussed and I don't really care what other people do or how they get their hits on target as long as they do just that. We have time and opportunity to either flip through pages and estimate when they don't line up with reality and we also have time to do the math.

This is my opinion that I've been forming since the OP. Simple is better. If simple to you is one page with some basic math that can be applied if the need arises or a text book full of pages for every possible outcome that has the number plane and simple in front of you... you choose. But I don't want to hike 7-8 miles with any more weight than I need to and I deffinatl6 don't want to be flipping through pages when I come up on an elk at 500 or 600 yards. If I can reference one sheet/card and estimate from there on simple shots then that's what I'm going to do, I don't want data I don't need cluttering up my (limited) thinking space.

Now there may be some spelling errors in there but I fully blame that on my S7 so let's not get triggered.