Target Shooting Matches, Discussion & Events > Field Target Gates
Shooting in the wind
Cloud 9:
As I shoot springers more in WFTF and get consistent POI while sitting, I am beginning to notice that when I miss it can't be attributed to me or the gun. Fellow shooters suggest that it is the wind blowing my shots off target. Here in north Texas, we shoot in mostly wooded venues, where the winds are usually partially blocked by trees and certainly variable in direction. I've read a book on shooting in the wind, but it was for NRA high power rifle at long range on open fields. I want to learn to shoot better in these conditions, so what are your recommendations?
Blue:
We were discussing this a bit in another post about wind's effect on pellets, there's some good info there.
I think it comes down to practice and experience (and I'm not saying I have a lot of either nor do I consider myself a good shot in the wind but I'm working on it).
Pick times to "play" with reading the wind where you can take multiple shots looking at how the wind effects your shots. When you change your gears from, "I think I adjusted correctly so I can make the shot I'm trying for" to "let's aim here and see where it ends up then see if I can make the second shot stick it" you end up having a lot of fun.
Oh yeah, AND you get a bunch of that practice and experience stuff along with the smiles, it's kinda like a bonus.
Blue
Habanero69er:
The aforementioned thread about shooting in wind.
http://www.gatewaytoairguns.org/GTA/index.php?topic=125188.msg1223689#msg1223689
michaelthomas:
Hi Jeff...it was nice to meet you at the Cajuns match.
I have a few ideas for you that I believe will speed you along with your wind understanding. Much of my FT wind understanding comes from my air rifle benchrest experience...and I have done my best to utilize what I already know to help with what I need to learn.
After looking at typical benchrest setups...I often hear people say things like, "Boy, with something like that...how can you miss?" They are referring to the fact that we use adjustable front rests and rear bags that effectively "lock" our rifles in place. As an example of that sort of setup...I can tell you that my BR rifle on its rest and bag placed on a concrete bench will shoot enlarged singe hole 25 shot groups at 27y indoors without ever looking into the scope. By this, I mean that I can point the gun at the center of the bull once, and load and fire 25 shots without ever looking into the scope again. Its that stable. So to answer the question of how can you miss with this setup...we introduce wind. The fact is...missing the 10 ring with a setup like this outdoors at 25m is actually very easy. BR is all about reading wind. If you have a good rifle and a good rest and bag that works well with your stock design...your only job is to read the wind and correct you POA so the pellet hits the middle.
To begin to understand the wind...I believe you must first know what you can expect from your rifle in zero wind conditions. After that, everything that happens beyond that is wind influence. I'm fortunate enough to be able to shoot indoors at 55y. Most people know someone with a shop, warehouse, or something where they can at least get indoors and shoot 25y. For FT, you are going to need to sit down and shoot 25 shot groups indoors in position and see how you do. Why 25 shot groups? Well, because the typical 3-5 shot group will not really tell you anything useful since a FT match is typically 60 shots. If you shoot 5 5 shot groups...you will likely notice that the groups size will be very different. If you shoot 5 25 shot groups, the size of the groups will likely be very close. What you are trying to determine is what size group can I count on from myself and my setup at a certain range. If you have never done this indoors, you will probably be a little shocked at your results. I know I was. It took an awful lot of practice on my positional shooting to develop something reasonably consistent. For myself and a very consistently accurate pcp...I can reliably hold a 5/8" outside to outside 25m 25 shot group from the sitting position indoors. The large percentage of shots will be inside 3/8", but there will always be the spoilers that conspire to enlarge the average. If my rifle was on the bench...all 25 would fit inside a circle half that size. So in essence...my holding the gun and sitting on the ground doubles the group size for a 25 shot group. With that knowledge in hand...you now know what you have left for wind...and unfortunately its not as much as we would like. If I double my distance to 55y...you can also double the indoor 25 shot group size. So in my case, I can count on most of my pellets being inside a 3/4 circle...but the spoilers enlarging the average 25 shot group to fit inside a 1 1/8" circle. At the typical KZ size of 1.5" at 55y...this only leaves 3/16" lateral drift from the center to make sure that all 25 pellets will reliably fall inside of the kz. Thats a little depressing...lol.
So how much wind does it take to move the pellet 3/16" of an inch at 55y? Surprisingly little. For us poor saps that are shooting at 12fpe we can expect a lateral drift of around .53" at 55y with only 1 mph of wind. Unfortunately...its practically impossible to detect a 1 mph wind without wind flags and other devices that we don't have at our disposal on the course.
For the 20fpe guys...the lateral wind drift for any given mph is approximately 1.65 times less. As a guy that shot Open class last year, I can tell you that 20fpe is a huge advantage...especially when the wind is near still and you cannot tell which direction it might be going. In conditions like that, you can hold in the middle and still knock the long targets down with regularity. With 12fpe, if you cannot tell which way a 1-2 mph wind is going...you will likely miss with a center hold at 55y.
Many of the guys that have been doing FT for a long time have somewhat of a sense of how much to hold off at a given distance for a particular wind. It took them a very long time to develop that sense, I'm sure. Fortunately, the less initiated can use an alternate method of wind drift estimation with just a little practice.
The first step is to be able to estimate wind velocity reasonably accurately. If you have no sense for what a 5mph wind feels like, I would suggest you pick up a Kestral hand held wind meter and simply carry it around with you wherever you go and take samplings of the wind periodically. After a short time, you will be able to put a pretty accurate number to what you feel and see. Its important to note that the wind you feel while standing up tall, will be roughly double what you feel in the typical sitting position. The lower you get to the ground, the less mph.
OK, so now you have a good feel for estimating velocity. Now you need a yardstick to put a drift number to the mph. Most guys in FT utilize distance. For example...if we know that a 1 mph wind puts us out .53" at 55y, then we can trust that a 4 mph wind will push us about 2.1". They use the observed KZ size to get a feel for distance. So if you want to hold 2" left...you can approximate 2" if you know the kz is 1.5.
The problem with this method is that the drift is not easily scaleable for distance. For example....our known .53" of drift at 55y per mph does not equate to .26" at 27y. Wind drift distance squares with distance. So if you drift .05" at 10y....you are going to drift .2" at 20. Its not an easy method for calculation. This type of method would require you to keep a chart of drift for each distance to make it easy. It also requires a reference distance so you can estimate well.
Mildots to the rescue. Most FT scopes have mildots or hash marks of some kind. These allow you to measure milliradians or MOA using the reticle. These measurements are angles. The nice thing about using angles instead of distance is that angles scale nicely. If you have to hold 1 MOA at 27y for a 1mph wind...you will have to hold 2 MOA at 54y for a 1 mph wind...and 1/2 MOA for a 13y 1mph wind. This is likely to all sound rather confusing if you are not accustomed to using your reticle. Its not particularly important that you understand the trig...just that you understand that it reliably works.
You must determine the mil or hash mark spacing on your particular reticle. Many scopes have documentation that will readily tell you. The very common Sightron with the MOA2 reticle has a 1 MOA spacing at 48x. Its also important to know that this spacing changes with magnification. I use a fixed power Leupold, so this is of no consequence to me. If you have a variable, but always shoot at the same power, it wont matter to you, either. Just determine the reticle spacing for whatever power you use.
Now you just need to put a MOA drift number to your wind mph. Just focus on what happens at 1mph, and you can easily do the math for any other number.
If you happen to be shooting JSB monsters at 20 fpe and near sea level...you are in luck. It just so happens that 1 mph of wind will move you the MOA amount of your distance to target moved 2 decimal places. For example...if you are shooting at a 50y target...the MOA holdoff will be .50 MOA per mph. If you are shooting at 23y...the MOA holdoff per mph will be .23. This makes it really easy to remember.
If you are shooting 8.4's at 12 fpe...the numbers are going to be different. 10y is going to be about .16 MOA per mph. If you only remember your 10y number...you will have all the info you need to make the simple calculations for any other distance and velocity.
Here is a quick rundown of how the procedure will go. I spend my time while my lane partner is shooting estimating the wind direction and assessing its velocity.
1. When I sit down...I range find the target. Lets say the target is 42y.
2. At 42y...you can now determine the MOA holdoff required for a 1mph wind based on your knowledge of MOA at 10y...which in my case is .16MOA. 42y is 4.2 times 10....so multiply your 10y MOA by 4.2. If you are not good with math...just get close. It will be a whole lot better than just guessing. So .16 times 4.2 is .67 MOA per mph. If you just used .15 MOA for your 10y number and rounded the yardage multiplier to 4...you would get .60 MOA per mph...which isn't too far off. Alternatively...you could just add the MOA numbers to your click chart...which is what I do. I'll post a pic of that later.
3. Now you take your estimated wind velocity and multiply it by your number you determined in step 2...which was .67. If I have assessed a wind velocity of 4mph...you multiply 4 x .67. This is 2.68 MOA.
4. Now look through your scope and count 2.68 MOA. Many scopes are 1 MOA per bar...so you would be holding off 2.68 bars.
This probably sounds complicated...but with a very small amount of practice it becomes automatic.
I absolutely guarantee you will knock down many more targets using this info compared to just guessing or not holding off at all.
Since we almost always shoot a short target first...we can glean wind info from the shorty to help us on the long one.
Short targets are mostly gimme's because the wind drift is less and the kzs are amply sized so we can usually stay inside without any significant hold off, anyway. Because the targets are close...we can also pick up where we hit them, too. If I sit down for a 1/2" kz target at 14y....I can guess my wind and do my calculations...then watch very closely where the pellet actually hits. Pull the target back up and measure where you aimed to where you actually hit with your reticle...then calculate backwards what the wind velocity was. You can then use this wind velocity number to give you a little extra help on the upcoming long target.
If you read through this enough times...I promise it will make sense if it does not right now. Follow the examples and just practice along. If you have taken the time to get a sense of wind velocities using the handheld meter...you will probably increase your hit rate by using this method a significant amount.
BTW...wind drift in MOA can reliably be found using chairgun.
I'll post a pic of my click chart. It has distance, click value, then wind drift in MOA per mph for each distance. Less on the spot math.
Hope this helps,
Mike
michaelthomas:
Here is my click chart with the number in parenthesis being the MOA value of wind drift per 1 mph.
Mike
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