If you have a wind going left to right at the firing line, and right to left at the target which do you hold for? Or do you just hold center? We had pretty much this at the last match, but it was a 1/4 value wind from behind.

- Thread starter ScottyS
- Start date

If you have a wind going left to right at the firing line, and right to left at the target which do you hold for? Or do you just hold center? We had pretty much this at the last match, but it was a 1/4 value wind from behind.

Wind down range is more important. As the bullet hurls toward the target and is bleeding off energy it will be more affected by down range wind than it will be by wind at the firing line.

Scotty, Ziebart what retical do you guys use?

Scotty, Ziebart what retical do you guys use?

It really depends on the individual situation, and how much of the mirage you can read. If you use the higher magnification, and focus the scope at different ranges between you and the target, you might see differences in the mirage at different places. Also, keep in mind the actual path of the bullet, not the straight line between you and the target. You can sort of "weight" the corrections in your mind based on your observations, take your best guess, hold, and shoot. This is where a LOT of practice on a 1000yd range with target pullers comes in handy.

In the past, I have used the MOA-graduated reticles, have some NPR2s, but I really like the NPR1 better. I also have some mil-dots. I am currently using a Mil-MLR scope on my .308, it's just as easy to use as the MOA/MOA setups, just retuning my head a little for the different values might take some time.

On my AR15 I have a nikon monarch 3-12x with nikons bullet drop circles on it. It is ok, but I really have not used the holdovers. It was bought because of price point, weight and magnification range. If anyone wants to know the MOA of the circles PM and I can send them out.

Interestingly enough, the wind at the firing line is **very important, because once deflected, the bullet will continue in that direction unless pushed otherwise**. People argue a lot about which wind to pay the most attention to. I say that it depends on the velocity of the wind and how much of the flight will be affected. A light breeze in one direction at the line will not affect the bullet nearly as much as a stiff breeze over the final 300yds in a different direction.

It really depends on the individual situation, and how much of the mirage you can read. If you use the higher magnification, and focus the scope at different ranges between you and the target, you might see differences in the mirage at different places. Also, keep in mind the actual path of the bullet, not the straight line between you and the target. You can sort of "weight" the corrections in your mind based on your observations, take your best guess, hold, and shoot. This is where a LOT of practice on a 1000yd range with target pullers comes in handy.

In the past, I have used the MOA-graduated reticles, have some NPR2s, but I really like the NPR1 better. I also have some mil-dots. I am currently using a Mil-MLR scope on my .308, it's just as easy to use as the MOA/MOA setups, just retuning my head a little for the different values might take some time.

It really depends on the individual situation, and how much of the mirage you can read. If you use the higher magnification, and focus the scope at different ranges between you and the target, you might see differences in the mirage at different places. Also, keep in mind the actual path of the bullet, not the straight line between you and the target. You can sort of "weight" the corrections in your mind based on your observations, take your best guess, hold, and shoot. This is where a LOT of practice on a 1000yd range with target pullers comes in handy.

In the past, I have used the MOA-graduated reticles, have some NPR2s, but I really like the NPR1 better. I also have some mil-dots. I am currently using a Mil-MLR scope on my .308, it's just as easy to use as the MOA/MOA setups, just retuning my head a little for the different values might take some time.

I made a cheat sheet for range estimation (MOA and MIL). I also put together some examples on using the pythagorean theorem. The PT will help you with angled shots and figuring out the true range to targets. It takes a pretty severe angle to seriously effect your shot but if effects your shot non the less. I'll post them once I get my notes scanned in.

Here are the formula's from Sniper Country (http://www.snipersparadise.com/marksmanship/range_est.htm)

I would post mine but its for a MOA based retical.

Range estimation in yards;

Height of target (yards) X 1,000**divided** by target size in mils = range in yards

Height or width (inches) x 27.77**divided** by target size in mils = range in yards

Range estimation in meters;

width or height ( in inches ) x 25.4**divided** target size in mils = range in meters

height in meters X 1000**divided** by the mil size of the target = range in meters.

Pythagorean Theorem

Here are the formula's from Sniper Country (http://www.snipersparadise.com/marksmanship/range_est.htm)

I would post mine but its for a MOA based retical.

Range estimation in yards;

Height of target (yards) X 1,000

Height or width (inches) x 27.77

Range estimation in meters;

width or height ( in inches ) x 25.4

height in meters X 1000

Pythagorean Theorem

Last edited:

Here's something i stumbled upon today. This answers the question we had last week about this thing.

Occasionally we get asked by a client what concern, if any, should they have when using the Angle Degree Indicator if the scope is mounted a scope base that has a minute-of-angle (MOA) tilt, such as the commonly used 20 MOA or 40 MOA Nightforce scope base. The answer according to Nightforce is none. Here’s why: There are 60 minutes-of-angle in 1 degree, so even a 40 MOA base is tilted less then 1 degree. When considering shooting angle for accuracy it is generally accepted that any angle less then 5 degrees is not a significant influence on reasonable accuracy. Therefore, any angle associated with a tilted scope base may be disregarded.

Last edited:

Ah, good old Pythagoras.

I use that formula all the time for game programming. You often need to know the distance between two things. It also works in 3 dimensions, or even 1,000,000 dimensions, but typically we don't work with that many since the real world is only 3D.

Right triangles are very useful items. They are composed of six parts, those being the three sides (hypotenuse, opposite side and adjacent side) plus the three included angles, one of which is the 90° right angle.

As an example, if we take Pythagoras' a bit further, we can use it to help us with range estimations on up hill and down hill shots, as well as with wind deflection.

For example, you are trying to make an uphill shot at a distant target and you have used your LASER range finder and it says you are 300 yards from the target. Do you hold for 300 yards and fire? If you do, you miss, shooting OVER the target because the actual distance the bullet must travel is less than the 300 yards the range finder gave you.

Why? Because 300 yard reading is the line of sight distance, and not how far the bullet is actually going to travel before striking the target, strange as that may sound!

If you know line of sight distance and you can figure out the angle up hill or downhill (using JF Comfort's improvised inclinometer!) you can use the formula: Sine of Angle A = the Opposite side divided by the Hypotenuse (S.O.H.) to find the vertical distance. Once you have that, you can then use the Pythagorean Theorem to find the true distance the bullet must travel.

In the drawing above, if your LASER range finder gave you 300 yards as the distance from you at Point A, to the target located at Point B, and using JF’s inclinometer, or a real one, you find that the angle between the ground at your feet and the target slopes upward at a 30° angle, you can then use your scientific calculator to figure out what the distance the bullet travels, which would be the line between you at Point A and Point C.

The Sine of 30° is .5 so we plug that into the equation to get: .5 = X/300

We can multiply both sides by 300 and figure out that X =150.

OK, so now we know the length of the side of the right triangle we call BC is 150. The Hypotenuse is 300. So we square 300 = 90000, and we subtract the square of 150 (22,500) from the 90000 to get 67,500. We take the square root of that find that the side of the ABC triangle known as AC is 259.8 yards long.

Call it 260. Hold for 260 and make the shot.

Same thing works for windage deflection.

The other two parts of the right triangle package that let you figure out what’s missing are:

C.O.A. = Cosine = Opposite Side divided by Hypotenuse, or a divided by c. In the triangle shown above, the opposite side is a, and the hypotenuse as always is side c, the longest side.

And:

T.O.A. = Tangent = Opposite Side divided by the Adjacent Side, or a/b.

You can remember the above ratios with the mnemonic “S.O.H-C.A.H.-T.O.A.) rhymes with Krakatau, the volcano that blew its top.

There are also three inverse ratios for finding the above as well.

Cosecant = Hypotenuse divided by Opposite Side

Secant= Hypotenuse divided by Adjacent Side

Cotangent= Adjacent Side divided by the Opposite Side

There are other applications for the above as well, such as figuring out how far it is across a river, or how tall a tree or mountain is, by constructing proportionate triangles.

But we’ll save that lecture for later, assuming anyone wants to know how to do it that is.

Wow...my brain hurts.

I can put you to sleep faster than bottle full of Lunesta and a quart of Jack Daniels combined.

I'm surprised, don't they teach this in school any more, or has the "new math" eliminated all this by teaching you to just ask an old guy?!

You think it hurts now, wait until we go into oblique triangles and the solutions for those, including the right angle solution method! :banghead:

I can put you to sleep faster than bottle full of Lunesta and a quart of Jack Daniels combined.

I'm surprised, don't they teach this in school any more, or has the "new math" eliminated all this by teaching you to just ask an old guy?!

I can put you to sleep faster than bottle full of Lunesta and a quart of Jack Daniels combined.

I'm surprised, don't they teach this in school any more, or has the "new math" eliminated all this by teaching you to just ask an old guy?!

they teach it...but like everything progress of technology. All i have to do is enter too function into the calculator and it does the rest for you, they teach it the long way but then allow calculators the second you figure it out. Plus you only require to take Algebra II/ basic trig in clark county....

they teach it...but like everything progress of technology. All i have to do is enter too function into the calculator and it does the rest for you, they teach it the long way but then allow calculators the second you figure it out. Plus you only require to take Algebra II/ basic trig in clark county....

They might find themselves out in a cornfield some day with a non scientific calculator and a need to solve a trig or algebra problem. :devil:

That's a shame. Math is so useful in so many areas of life. I don't have any problem with using the calculator, but they need to make sure the kids understand the principles behind solving the problem.

Im now racking my brain re-learning this stuff i should already know only because it relates to something that interests me.

Last edited:

Only if my teachers would have told me this would be used in rifle and other shooting sports i would have stayed awake in class.... who wants to become a rocket scientist, all NASA did while i was in school was blow up shuttles,loose mars rovers and launch blind telescopes.

Im now racking my brain re-learning this stuff i should already know only because it relates to something that interests me.

Im now racking my brain re-learning this stuff i should already know only because it relates to something that interests me.

He was a former MARINE and had been a Mechanical Engineer before retiring and getting his teaching certificates. He was also a competitive shooter, and a hunter.

So when he put forth how useful math was to a shooter, I listened! He also mentioned how useful it was to Gunsmiths and Hot Rodders. I had heard that before from the two old master smiths who taught me the trade, one of whom was a retired master tool and die maker before becoming a gunsmith. He preached it more than the 5th generation gunsmith did, but both emphasized it.

Also heard it before from my Dad, when I started building my own hot rods, he showed me how math was useful for building the car, figuring weight distribution, calculating volumetric efficiency so that my engine wasn't over carbed, figuring gear ratios, brake swept areas, you name it.

If you want to brush up on it, there are some good books out there for under $10 each, saw them all in Wally World's $1 book clearance shelves just last week also.

Stop by a book store, or Wally World and pick up copies of:

Painless Algebra

Painless Geometry

Painless Trigonometry

All published by Barron's. Easy to spot on the shelves, they are bright yellow. They give clear, concise explanations of the formulas, theorems, etc. along with memory tricks to help you retain it, and with practice problems to help sharpen your skills.

Those are the books I gave to my young cousin's in Las Vegas a couple of years back when their parents asked me to tutor them in math because the teachers and curriculum in that subject in their high school was so weak.

The boy wants to be a Mechanical Engineer, although he just signed a contract to play pro hockey, so that may be put on hold.

The girl wants to fly fighters, she's into aviation, and is going to a private school now that has that on the curriculum. Both careers require a strong foundation in math.

Between the tutoring and studying those books, they both pulled straight A's for all three courses.

The Dummies Series for each of the three are fairly good also.

And there are quite a few good web pages out there that explain all the various branches of mathematics.

We just have the wrong school books.

If my math books had those pictures in them back in the early 60's, a lot more guys in math class might have passed. . then again, maybe not.

After reading all of this I'm buying a

NF 22x and a B.O.R.S. system

Thats Barrett optical ranging system or something like that..:ihih:

NF 22x and a B.O.R.S. system

Thats Barrett optical ranging system or something like that..:ihih:

Analog doesn't fail. So it's nice to have as a back up to the high tech.