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Location: Misouri
Joined: 11/30/2005
Posts: 365
Doping the wind

Yes there is but I don't know it . Sorry.

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Location: North Louisiana
Joined: 12/08/2006
Posts: 120
Reading wind?

All the more reason for those of you wanting to learn to take up NRA HP shooting and then you'll be rubbing elbows with the best class of shooters in the world! Reading or estimating wind on rifle ranges is an art not learned from reading a book or from listening to someone whom doesn't have a lot of experience that has not learned the art. Wind moves in cycles throughout the day; one minute it's maybe at 5-6 mph from 2 o/clock....the next minute it's changed velocity and vectored around to between 3 or 4 o/clock! Or it may be doing what's known as 'fishtailing' whereby it's coming from 5 o/clock and then moving around to the 7 o/clock position. Wind conditions are seen quite easily through a spotting scope; not one of 45X or 60X I might add but rather a power of around 25X will work much better. Mirage which is nothing but the flow of the wind seen through varying layers of air density shows up through a spotting scope as heat waves which are moving from one side or the other or.....the heat waves may be moving upward which indicates that the wind has died. This condition is known as a 'boil' condition. If the wind is coming at the shooter from either the 12 or 6 o/clock position this can also give the appearance of a 'boil'. The best way to learn how to read/guage wind conditions is to lay down next to a good longrange shooter and focus your scope such that you can observe the shot strikes on the target face and the mirage while shooting is taking place. One whom wishes to learn should have a plotting sheet so shot locations can be plotted on the target face and compared to what the mirage/wind was doing over the course of the string being fired. Mirage can best be seen in conditions of heat and humidity and of course in conjunction with sunlight. Mirage can be 'read' up to a windspeed of approximately 14 mph velocity but beyond that the heat lines flatten out and cannot be read! Then is when experience with wind flags commences as that's the best indicator that a shooter has after mirage lines flatten out! I mentioned a 'boil' condition earlier and something else needs to be said pertaining to it! When the mirage begins to 'boil'....one of two things is about to happen aka it will either eventually pick up from the same side that it was running/coming from or.....it will swap directions 180 degrees! And here is where a shooter has to know his DWZ or Dead Wind Zero because the shooter will have to CHANGE SIDES on his windage scale and if DWZ isn't known....YSOL aka You're Shxt Outa Luck for getting back on target!! There is another option available to the shooter if the wind reverses and that is to wait the wind out to see if it will change back to it's previous condition! I have waited out these conditions many times and usually if the wind is going to go back to it's previous condition it will usually do it within 5-8 minutes lapse! To be able to do this depends on how long the shooter has remaining on the time allotted to shoot the event! All of this pertains to shooting with aperture sights such as is done in NRA HP shooting! No scopes are allowed except in maybe a match such as The Wimbledon Cup Match or a match designated as an Any Any Match which means Any Rifle, Any Sight! Maximum caliber allowed is limited to .338 in LR events I might add! You won't learn wind reading shooting in still conditions! You have to shoot in windy conditions to learn and by keeping a good data book.....and the amount of windage used for certain conditions.....and by paying attention to detail....the process becomes more familiar! If one is shooting at a distance of 1000 yds. or so.....the wind that is MOST IMPORTANT lies between the shooter.....and the 500 yd. line! If one is shooting from 600 yds. the wind between the shooter and the 300 yd. line is the MAJOR WIND CONDITION AREA! There are variables to this rule...such as....if one were shooting from a location that was protected from the wind such as a steep canyon but the last half of the distance being shot at was where the bullet was breaking out into an area where there was a drastic wind change.....THEN.....the latter half of the distance being fired from would be most important! But...this is an unusual condition and the first rule mentioned above applies 99.9% of the time!

Don Fischer's picture
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Location: Antelope, Ore
Joined: 03/24/2005
Posts: 3190
Doping the wind

Rick,

Great post! Tell me something tho. You mentioned something that the guy here in town did and I think I found on the CMP site. Everybody say's to measure the wind half way to the target, why is that? One more thing. I read about the DWZ and I'm thinging it's the windage adjustment at zero wind? I took this new scope I got and centered the crosswires prior to mounting. As I recall, I had just over 200 elevation click's and just over 100 windage clicks with the crosswires centered. Then I installed a one piece Leupold base with windage adjustment and zeroed with that rather than the windage adjustment. With load devepolement I'm using the windage adjustment but don't move it much. The turret's are adjustable so that after sighting in, they can be loosened and set to zero. Now sighted in I can adjust as needed and still return to zero. Am I doing this right?

EDIT:

I was just reading back thru Remington's post's and a thought occured to me. Perhaps wind is read at half distence because it does no good to read the wind at the target? DUH, bullet has arrived so wind is out of it! And by the way, do you know how to figure out the "constent" Remington spoke of for the bullet used?

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Location: North Louisiana
Joined: 12/08/2006
Posts: 120
Reading wind?

Don

You're doing things right! Most important when working with say a Leupold scope or any scope with target knobs is to center the reticule (windage wise) and then use the adjustable mount to get fairly close. If the windage IS NOT CENTERED first (the reticule) and is offset.....the amount of elevation that you have would be limited as the elevation reticule would only be moving from say.....the 2 o/clock to the 4 o/clock position rather than from 12 to 6 o/clock! After obtaining a tentative wind zero using the adjustable mount....then the finalized zero can be accomplished using the turrent knobs. Then it's a simple matter to loosen the screws to the 'barrel' on the target knobs to move the windage knob to the "O" position. What must be kept in mind is as far as a windage zero is concerned is that the zero you obtain at 200-300 yds. will not normally be the same zero that you have to use from say 800-1000 yards because the bullet will drift right (with right hand twist barrels) as the distance increases because of precession! The rotation or torque of the rifling twist is such that the projectile is moved to the right. If I recall correctly the precession of a .308 round with M82 Match ammo is about 14" at 1000 yds. With longer/slower bullets like I shoot in my Sharps and HiWall rifles....the drift from 1000 yds. is around 40-45"! So if you're going to work off of a close range zero.....you will find that you will have to take possibly a minute or so of movement to the left....under a no wind condition to be on target! The reason the wind is most important during it's first stage of flight (the movement of air between the shooter and half way to the target) is one basically involving math! The farther the bullet is blown off course during the earliest stage of flight means A LOT MORE DISTANCE IT WILL BE OFF TARGET the further it goes!! If this is difficult to grasp.....plot it out on a sheet of paper and it becomes crystal clear!!

As for the 'constant'....I'll have to go back and read that post to find out what's being said!

Don Fischer's picture
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Location: Antelope, Ore
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Doping the wind

I think there's a very good lesson here Rick. Your talking about the bullet drifting from torque of rifling twist. I have always noticed in my hunting rifles that ammo sighted in at 100 yds was never right on at 300yds. What I finally did was to work up a load at 100yds then sight in the rifle at 400yds. Maybe I should do that at closer to 300 as I seldom shoot much past 200 to 250 yds at game. Here's an example. I was using 129 gr Hornady's when I started this long range stuff and the rifle was sighted in at 2" hight at 100yds per a readout on my cronograph using a max point blank range at a 6" target. I then used CG's method of determining click's at 400 yds with the drop my cronograph gave me, 18.3" drop was 18 clicks putting me 1/4" low. Elevation was so close to right on it was scary but, the bullet had drifted to the right about 3". There was no wind so I was a bit perplexed and went back to 100 yds and shot again. Right on. Now I understand it. While I don't shoot game at those ranges, the lesson's learned on paper are great, once someone explains to you what you saw.

I might explain my reasoning for the 6" MPBR at a 6" target. I'm looking at that "sporting rifle match" thing and the closest target is 175 yds and the small target is 8". I'm thinking that using a MPBR on a 6" target might well take all estimations out of some of the shots so that I don't have to start adjusting for elevation to soon. ie: with the 140 gr SMK at 2800, which I'm getting now, at 325 yds the bullet will be -7.7" which means I hold on the top of the target at 325 yds for a hit. I can hold on the center of the target to 275 yds.

Thank you,

Don

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Location: North Louisiana
Joined: 12/08/2006
Posts: 120
LR Shooting

Don

Invest in a 4.5x14X Leupold with B&C reticule and you'll be amazed as to what you can do with it!! Thumbs up lol

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Location: Mobile County, Alabama
Joined: 09/09/2007
Posts: 310
Doping the wind

Reading mirage is how most competitive shooters do it. It allows instant and more accurate feedback than any other method. It also allows you read at any distance you can see.

Some are better at it than other and my scores show I need more practice. eye roll

Don Fischer's picture
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Location: Antelope, Ore
Joined: 03/24/2005
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Doping the wind

I know what you mean. I was told to focus the scope half the distence to the target and read there. Also was given some wind values for moving grass ect. I'm not very good at it! Cry

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