Home Forums Hunting & Shooting Ask The Gunwriters The Complete Range Estimator

Somebody oughta write a book of this title! If it is already in print please let me know. But this is what I would like to pick up and read-

A book on range estimating that has a brief review of trig so I can understand the terms. (haven't done that stuff since high school)
Then the history of range estimating. Crude devices you can improvise and use.
Then a review of modern range estimating "stuff" going over every option out there from lazers to German WWII bino's and whatever else there is, including a couple of chapters on mildots and other reticles.

Did that John Antanines guy, (spelling?) go over all that in his book on scopes? What is the title of that book? A friend from Montana I worked with over seas told me about that book but I have never seen it.

Thanks y'all

You've been reading my notes!

I'm working on an article that will cover most or all of what you suggest. It'll include (a) the simple but useful gizmo that Dad made for me in the early 1940s, (b) the Army's pre-WW1 Weldon range-finder (I have one), for which I've just acquired the 1909 Ordnance Dept manual, (c) three WW2 military convergence range-finders that I have (England's Barr & Stroud, Switzerland's Wild, and Sweden's Nife), (d) a cheap hunter's model that I used to have, and (e) a modern laser RF that I hope to be able to borrow (probably the latest from Swarovski).

Unfortunately, I don't have a surveyor's transit (wish I did!) but may be able to borrow one. There are two ways to use transits -- one transit with a stadia rod and two transits with any target and a chain. I also don't have a chain (wish I did) but do have two kinds of surveyors' calibrated "ropes," which I'll show in the article's photos.

There's an old method of using your fist or fingers, but I don't know it and am waiting for a friend who knows it to edify me.

A brief explanation of the trig is necessary and integral. Also how to use 'em to best advantage, their pros and cons, etc. Just hang-on a little longer.

FWIW, I've used some of the above methods professionally as a field arch�ologist in the Arctic and as a surveyor. My son -- "Skalkaho" at the Campfire -- is a land surveyor with university training and field experience with laser and infrared "total stations" and GPS surveying. I know just enough about these to mention 'em here, so they won't be covered in my article. It's best not to advertise one's ignorances too widely.

Don't have a title for the article yet. Any suggestions?

Fantastic!

Once your article is done where will it be published? Why not put it together into a book form? I'll buy it for sure!

Title??? I always liked those titles from the 1600's you know the long ones, how about:

"A Mathmatical and Engineering Primer on the Field Estimation of Range for the Ardent Hunter and Defender of Constitutional Law, Differing Methods; Modern, Mechanized and Crude, Diligently Compared and Assessed, Including Anotation and Extensive Bibliography."

heh heh heh

Hey I like that!

For now, here's a brief review of the trig that most classic range-finders depend on.

� The three lines of a right triangle form three angles, one of which is 90�, and the total of all three 180�.

� Customary terminology calls the short leg next to the 90� angle the adjacent side (A).

� The longer side next to the 90� angle is the opposite side (O).

� The side that connects the ends of A and O is the hypotenuse (H).

� The most-used ratios of the sides to each other are the sine (S), the cosine (C), and the tangent (T).

� Each of the two smaller angles has its mathematical S, C, and T -- and standard reference tables list 'em.

� The classic school-boy mnemonic for remembering these ratios is "remember Chief Soh-Cah-Toa."
S = O /H
C = A/H
T = O/A

� The Pythagoras Rule reminds us that A� + O� = H�.

From there on, the trig becomes simple algebra. Using the lengths of any two sides, you can figure the length of the third side. Using the length of one side and the S, C, or T of the angle, you can figure the length of a second side -- and then find the length of the third side.

To check the results of your first practice figuring, start with a 30�-60�-90� triangle. The hypotenuse (H) of this particularly useful kind of right triangle is twice as long at the adjacent side (A). Start with a known A or H, and simple algebra will give you first the length of the other side (H or A), then from these, you can figure all the rest.

Leica LRF 1200 Scan...

Matt, you are too funny. <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />



That's what I use.



I'm afraid of those darned hypotenuse things. I've been to Africa a few times and they kill more people than crocodiles. Man, it's the Leica 1200 LRF for me!



Steve

Don't forget the old country carpenter's 3,4,5 rule.If a and o are 3 and 4,or 4 and 3,then the h"thang" is 5.Obviously it works with any multipiles of the three basic numbers.
I use it to remember the formula.I reckon everbody on here already knew it but figgered I didn't so that's why I mentioned it.
I've exhausted my typing finger and my store of math know-how in this one post.
You got business over on the gunwriter forum Ken.

So many scribblers, so few adults! <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

Just couldn't pass up the opportunity.

Golly, it's been a while since I thought about the Pythagorean theorem. In truth, it is one of the few perfect things in our reality, so I shouldn't make jest.

But I did. <img src="/ubbthreads/images/graemlins/grin.gif" alt="" /> <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

I knew when I wrote that post that somebody'd come right back with some kind of pun on hippopotamus -- wondered as I was writing it (a) who'd post the first one and (b) how clever it'd be. Not bad, Steve! <img src="/ubbthreads/images/graemlins/grin.gif" alt="" />

I've really found it handy. Used it extensively in 1958 to develop the cutting pattern for the Ken Howell mountain tent and again several years ago to design my Pythagoras level ("P-level"), which is more sensitive and accurate than a bubble in a vial. I've used it frequently with a passel of lesser projects through the intervening years -- sometimes with the 3-4-5 triangle, sometimes with the 30�-60�-90� triangle, occasionally with the 45�-45�-90� triangle. It's nice, though, when a simpler procedure or gizmo gives us the same results with less bother. If I were developing a cutting pattern for my tent today, for example, I'd do it in AutoCAD -- and save days, pencils, paper, erasers, and cuss words.

When it comes to trophies, come to think of it, I'd rather have a few busy hypotenuses around than the head of a dead hippopotamus on the wall.

"Don't have a title for the article yet. Any suggestions?"

How about "Going the distance"

Or "The measure of a hunter"

Good suggestions! Thanks!

I like 'em short -- what do you think of "How Far?" as the title?

(Just this minute thought of it. Sometimes the simple and the obvious take longer to think of.)

Ken,

Are you/we able to post AutoCad drawings as attachments on 24 Hour Campfire? If so, how?

Thanks

How about "Aim Point" or "Point of Aim" for a title?

I would really like to see Leica add the ability to input your cartridge ballistics and have the dang thing calculate the offset. Instead of using a rangefinder you would have a targeting system. Adding a device to measure the angle off normal to the earth (inclinometer?) would take all this up hill/ down hill guessing out of the range estimate. The math is very simple so it wouldn't take much computing power. I'm thinking inputting a muzzle velocity and bullet B.C. would be all that is needed given a distance and angle. Including wind drift information for the specific target distance would be an added bonus. If one got real anal, you could add a thermocouple for temperature related offset. I'm sure the military is already doing all this and more.

Yes. It's so easy, even I can do it.

With the AutoCAD drawing on-screen, enter the command "jpgout" and follow instructions to save the drawing as a *.jpg file.

When you post a Campfire message, attach the *.jpg file.

See the AutoCAD *.jpg drawing attached to this post, for example.

Here's another, just to show how easy it is.

Thank you for the reply. I have AutoCad Lite 2000. When I entered "jpgout" on the command line I got back "unknown command". When I went to help I could not find "save as jpg". Do you have fullblown AutoCad, or the low calorie version like me? Please bear with me, when it comes to computers, I am as dense as they come.

"How far" is great, Ken! In the past I dubbed some of my articles dealing with range estimating and long shots "Wie weit ist weit?" (How far is far?)

Regards
WR

As a former member of Autodesk's Author and Developer Network (nothing stranger has ever occurred in this world!), I have all the incarnations of AutoCAD. The only one that I use is the full but general or basic version -- not the Lite, the mapping, the architectural,or any of several other special adaptations. Heck, it's all I can do to barely get along with the basic version. As I wrote in my big blue book, AutoCAD is such a huge program that using it to make cartridge drawings is like using the old Goodyear blimp hangar to keep my lawn-mower dry.

You might be able to post your AutoCAD Lite drawing by "capturing" it off your monitor screen with a program like FullShot. I'll try it and see what the results look like. (Later.)

Here (attached) is a FullShot "screen capture" *.jpg version of an AutoCAD *.jpg file that I posted above. I won't really know whether this'll work, or how it'll look, until after I've posted it. So you and I can see together.