Gun mph for wind holds in the field

[VandelayIndustries]

I’ve read through a bunch of threads on mph gun and the corrected wind roses and brackets/charts. I understand how to get my gun mph with the G1 bc, easy enough. After that I’m a bit confused how the rest all fits together. Do you use the mph gun method: Full value wind speed / mph gun= multiplier Then multiplier x decimal yard value (.7 for 700 yards etc) = full value wind hold then you have to multiply that by your wind angle %…. If that’s all right that’s a lot of math in the field.

Or just use the corrected wind speed angle rose, use that corrected wind speed number in conjunction with a premade wind bracket for your gun mph and that’s your hold?
Example. 17mph wind at 11 o’clock is a 9mph wind. You have a 6mph gun. Shooting 200 yards.
Bracket1 (6mph). Bracket2 (12mph)
.1(@100). .2
.2(@200). .4
. So your wind hold would be .3

I’m sure I’m missing something, appreciate any help.

 

[HOOFER]

I’ve read through a bunch of threads on mph gun and the corrected wind roses and brackets/charts. I understand how to get my gun mph with the G1 bc, easy enough. After that I’m a bit confused how the rest all fits together. Do you use the mph gun method: Full value wind speed / mph gun= multiplier Then multiplier x decimal yard value (.7 for 700 yards etc) = full value wind hold then you have to multiply that by your wind angle %…. If that’s all right that’s a lot of math in the field.

Or just use the corrected wind speed angle rose, use that corrected wind speed number in conjunction with a premade wind bracket for your gun mph and that’s your hold?
Example. 17mph wind at 11 o’clock is a 9mph wind. You have a 6mph gun. Shooting 200 yards.
Bracket1 (6mph). Bracket2 (12mph)
.1(@100). .2
.2(@200). .4
. So your wind hold would be .3

I’m sure I’m missing something, appreciate any help.

An 11 o’clock wind at that range is unimportant.

But As you said .2 or .3 hold edge of said target

For times when I can’t use a ballistics solver for that shot. As a redundancy
I use a pre printed chart on my stock with a 3/9 o’clock 5 mph wind and multiply as needed. For every degree (hour) it’s off of 90 degrees (3/9oclock) and my 100 percent wind value.

2 o’clock is 66%. 1 Is 33%. 12 is 0.

So if my 17mph 200 yards. With a 9 o’clock wind hold is .7 I’d revise it by 2/3 and be at .2/.3


Not sure of the MPH gun method. Seems overly Complicated.

Josh.

 

[VandelayIndustries]

I know it’s unimportant at 200 I just didn’t want to type out a big chart… I’d just like to understand it fully

 

[HOOFER]

I know it’s unimportant at 200 I just didn’t want to type out a big chart… I’d just like to understand it fully

Gotcha. Yeah I’ll have to check it out.

What are the benefits of the MPH method vs having it exact for your gun?

Assuming this is for field expedience when no tech is available. How are you measuring a 17mph wind? That’s a very specific call.

 

[_Windrider_]

Gotcha. Yeah I’ll have to check it out.

What are the benefits of the MPH method vs having it exact for your gun?

Assuming this is for field expedience when no tech is available. How are you measuring a 17mph wind? That’s a very specific call.

The gun moh is a field expedited method to get you on target. Basically the formula is this (seems complicated but this is the long form. Once you understand what I’m actually saying it’s much faster).

((Crosswind speed/gun mph) x.1) x range/100

So let’s say a 10 mph wind (full value….which is 100% crosswind) gun mph 5 and target is 800 yds.

(10/5).1 x 800/100=

(2 x .1)8 =

.2 x 8 = 1.6 mils of hold

 

[VandelayIndustries]

The gun moh is a field expedited method to get you on target. Basically the formula is this (seems complicated but this is the long form. Once you understand what I’m actually saying it’s much faster).

((Crosswind speed/gun mph) x.1) x range/100

So let’s say a 10 mph wind (full value….which is 100% crosswind) gun mph 5 and target is 800 yds.

(10/5).1 x 800/100=

(2 x .1)8 =

.2 x 8 = 1.6 mils of hold

And that’s for a Full value wind right…. So then would you take that 1.8 and multiply it by whatever value the wind is coming from?
So a 2 o’clock wind would be 60% of that? 1.8x .60 = 1.08 or 1.1

 

[_Windrider_]

And that’s for a Full value wind right…. So then would you take that 1.8 and multiply it by whatever value the wind is coming from?
So a 2 o’clock wind would be 60% of that? 1.8x .60 = 1.08 or 1.1

Yes pretty much. Or you can think of it as a 6 mph wind instead of 10 mph because really what you are worried about is the crosswind component. It just so happens that a full value wind is a 90 degree crosswind.

Does that make sense? A 10 mph wind at 2 o’clock would be a 4 mph headwind and 6 mph crosswind so really the 800 yd answer would be closer to .9 because we are dealing 5 mph + 1 mph extra.

5/5 x .8 = .8 then add the .1 maybe for the extra 1 mph. Or don’t and just favor into the wind a bit.

Just remember this is for shooting big steel plates where hitting a bullseye isn’t the objective but rather just getting a hit like in a comp. Hunting or hitting a flipper may require more precise numbers.

 

[acudaowner]

42 ?

 

[HOOFER]

Yes pretty much. Or you can think of it as a 6 mph wind instead of 10 mph because really what you are worried about is the crosswind component. It just so happens that a full value wind is a 90 degree crosswind.

Does that make sense? A 10 mph wind at 2 o’clock would be a 4 mph headwind and 6 mph crosswind so really the 800 yd answer would be closer to .9 because we are dealing 5 mph + 1 mph extra.

5/5 x .8 = .8 then add the .1 maybe for the extra 1 mph. Or don’t and just favor into the wind a bit.

Just remember this is for shooting big steel plates where hitting a bullseye isn’t the objective but rather just getting a hit like in a comp. Hunting or hitting a flipper may require more precise numbers.

I guess I follow. I just am curious how this is “easier” if I need to figure out what MPH my gun is. I could just as easily figure out what my 5mph full value hold is.

What is the trick to figuring out your gun info?

looking down at my chart. Knowing it’s a .3 mil hold with a 5mph full value wind.

Doubling it for 10 MPH. And holding. .6

If it’s 2 ockoock it’s .4 If it’s 1 it’s .2. If it’s 12 it’s nothing

Thanks for the Info.
Josh.

 

[_Windrider_]

I guess I follow. I just am curious how this is “easier” if I need to figure out what MPH my gun is. I could just as easily figure out what my 5mph full value hold is.

What is the trick to figuring out your gun info?

looking down at my chart. Knowing it’s a .3 mil hold with a 5mph full value wind.

Doubling it for 10 MPH. And holding. .6

If it’s 2 ockoock it’s .4 If it’s 1 it’s .2. If it’s 12 it’s nothing

Thanks for the Info.
Josh.

The gun number is essentially the tenths digit of the G1 BC. So 308 is approx a 4 mph gun. It’s one of many methods and your number may vary if you are pushing your pills faster than standard.

Nothing is more accurate than getting actual data.

 

[Matches Malone]

I guess I follow. I just am curious how this is “easier” if I need to figure out what MPH my gun is. I could just as easily figure out what my 5mph full value hold is.

What is the trick to figuring out your gun info?

looking down at my chart. Knowing it’s a .3 mil hold with a 5mph full value wind.

Doubling it for 10 MPH. And holding. .6

If it’s 2 ockoock it’s .4 If it’s 1 it’s .2. If it’s 12 it’s nothing

Thanks for the Info.
Josh.

This method isn’t new. It’s been around for awhile. It’s called quick wind in most circles. They even added it to the kestrel.

It’s quicker because you want to figure out what your “mph” is of a particular gun ahead of time. Then it allows you to adjust based off that in your head. Assuming a no wind zero and having correct dope.

You’ll just have to remember to add in in your extra .1 at certain distances.

 

[HOOFER]

This method isn’t new. It’s been around for awhile. It’s called quick wind in most circles. They even added it to the kestrel.

It’s quicker because you want to figure out what your “mph” is of a particular gun ahead of time. Then it allows you to adjust based off that in your head. Assuming a no wind zero and having correct dope.

You’ll just have to remember to add in in you extra .1 at certain distances.

Good to know appreciate the info can’t have too many tools in the bag.

 

[iceng]

Calculating mph rifle

At a recent match, many on my squad were describing their wind calls in terms of mph, by saying eg: I used a 5mph wind( rather than describing it in terms of mils). These were good shooters doing this. (I just got on their squad by accident). Where can I learn about this technique, and...

www.snipershide.com

Lowlight did some videos on this. Hope its useful to you.

 

[Jack Master]

I guess I follow. I just am curious how this is “easier” if I need to figure out what MPH my gun is. I could just as easily figure out what my 5mph full value hold is.

What is the trick to figuring out your gun info?

looking down at my chart. Knowing it’s a .3 mil hold with a 5mph full value wind.

Doubling it for 10 MPH. And holding. .6

If it’s 2 ockoock it’s .4 If it’s 1 it’s .2. If it’s 12 it’s nothing

Thanks for the Info.
Josh.

The "easier" part is you don't need to look up you hold for distance. If I know I have a 5mph gun (similar to your data chart) my 5mph wind hold at 400yds is 0.4 and at 600 its 0.6. See how that value coordinates with the distance? This is the part that makes the system work mentally. I do not need to ever look at a data table for my wind holds. I might still need to use a wind rose but never a data table.

The trick to fingering out you gun MPH is finding what wind speed makes the holds match the distance.
What wind speed (at 9 or 3 o'clock) makes the chart below work? Use your ballistic calculator to figure this out.
100yds = 0.1
200yds = 0.2
300yds = 0.3
400yds = 0.4
500yds = 0.5
600yds = 0.6
(after 600 this might start to jump or change)
Once you find this wind speed - that is you gun mph. Its always the same unless you change your loads or change about 5000 DA.
(308s are usually 4 or 5 mph, 6.5 creeds are 5 or 6 mph, 7 Rem mag can be 7 or 8mph)
If you double your gun mph you will see the wind holds double too. This is your wind brackets. 5-10-15 is 1,2,3 bracket for a 5 mph gun.

so the wind calling process goes
Turn wind angle into cross wind value (use wind rose)
How many wind brackets are you in (5 mph gun in 7mph corss wind is 1.5 bracket)
200 yd target (0.2) is 0.2*1.5 = 0.3wind hold
600yd target in the same direction and wind is 0.6*1.5=0.9 wind hold.

See the trick here - No charts needed. All you wind holds are memorized or calculable by remembering one number.

 

[Gemsbok]

I haven't used my wind instrument much yet, so please bear with me.

Can one just measure the cross-wind component instead of calculate it?

It's my understanding that in normal use the wind meter is rotated around a vertical axis (pointed at the wind) to measure the direction and magnitude of the wind. If one were to hold the wind meter stationary and oriented to measure only the 3-o'clock fraction of the wind (that is, the fraction perpendicular to the direction of fire), one could conceivably skip the wind-rose/MPH/trigonometry and just use the full value holds.

Has anyone tried this?
Does it work?

 

[Emerson0311]

I haven't used my wind instrument much yet, so please bear with me.

Can one just measure the cross-wind component instead of calculate it?

It's my understanding that in normal use the wind meter is rotated around a vertical axis (pointed at the wind) to measure the direction and magnitude of the wind. If one were to hold the wind meter stationary and oriented to measure only the 3-o'clock fraction of the wind (that is, the fraction perpendicular to the direction of fire), one could conceivably skip the wind-rose/MPH/trigonometry and just use the full value holds.

Has anyone tried this?
Does it work?

No, it doesn’t. For the rule of thumb folks the % wind values from 12-3 are easy to remember. Wind meters are designed to measure wind straight through.

 

[gonzaga]

Using a wind meter to get the wind is easy...you can turn it until the propeller stops turning, that is the direction the wind is coming from. Here in NE NM at the coal canyon match, the wind switches directions....ALOT...
The gun MPH works, I start adding a tenth at 700yds. So .8 at 700, and .9 at 800 etc. At 6600 feet it works for me.
Frank has some great videos, as does Rifle Kraft...you tube is your friend.

 

[Rodney65]

For me I don't usually use a wind meter while actually shooting, usually only when I am in a flat open area with no obstructions near me or the target. I use a wind meter when I am near wind indicators like trees, tall grass, flags, etc. to see what they look like at different wind speeds in mph and then when making a windcall I look downrange to see what the indicators are doing.

Even though I usually use meters for range I use mph for wind speed as it's what I started with. I know 3pmh is barely noticable, 5mph is where it noticeable and could blow around loose paper, 7-8mph small poplar branches with leaves start to shake and the wind becomes audible, 10mph is where it could be called "windy" out and pine trees start to sway.

All my baseline holds are 10mph/90° holds and I adjust from there. If I am shooting at 600 meters my 10mph wind hold may be 1.0 MRAD. If the wind is only 6mph at 45° that 1 mil gets multipled by 0.6 to give me a 6mph value and then again by 0.7 to give me the 45°/1:30/4:30/whatever value giving me 0.42 which to me is 0.4.

To me this is simple as I only need to have one hold on a range card. It does involve rounding numbers a bit but I will never be able to judge the wind speed and direction precisely enough between me and the target that I will not be getting only a rough estimate.

One instructor I shot with was all about meters per second. His logic was if you saw something drifting in the air like smoke or dust you could actually watch it for one or two seconds and see how much ground it covered. He had another instructor discharge a fire extinguisher in varying wind conditions to demonstrate this. He also advocated describing wind indicators the way they looked to you with words/adjectives you understood and could remember. That one snippet of advice made wind calls a lot easier for me.