Home Forums Birds & Dogs Shotguns The effect of wind on shotguns patterns!!

We all know wind has an effect on shooting. But this fall I had a really crazy experience.. Last night looking for my last birds, I jumped a nice covey and squeezed of a load of Fed. 3 1/4-1 1/4 -6's.. To my surprise, two grouse crashed to earth!! I have had that happen a few few times before. They crossed as I fired.. But that is not all.. The night before in a horrible wind storm, I was getting ready for the hunt .. Had the 870 but not loaded.. I really let the dogs out to go pee.. They ran directly into a big covey of grouse.. Several took off, as I walked over several more flushed.. I figured that was all, but continued to walk toward the spot.. The dogs put up two more.. They were crossing pretty far, but I decided to try one shot.. Swinging far a head of the first grouse, I squeezed of a WW load of 3 1/4- 1 1/4- 5's.. To my surprise the grouse crashed to earth.. To my utter amazement , the second bird maybe 6- 8 feet behind also fell.. It was dead.. The first down but still alive.. I knew wind had a part to play in shooting, but I never dreamed it could so completely destroy a shotgun pattern...

WCH

Since they were "far out" you probably had at least 9 feet of shot string..I would guess your lead was perfect to have the behind Bird fly into it....High winds at distance can mess with the pattern, but my guess would be it was more about timing on your part.

Battue, what your telling me is I hit the first bird, and by the time the rest of the shot string got there it hit the last?? They both fell at the same instant it looked like.. Just interested?? Thanks..

I don’t really buy the shot string thing. Suppose your shot string is 9 feet like you state. At 1,100 FPS that means the last pellet arrives 0.00818181 seconds after the first pellet. Top speed of a grouse is about 40 mph, which is 58.7 FPS. Assuming top speed and a direct 90 degree crossing shot, the grouse travels 0.48 feet, or about 5 3/4 inches.

1,100 FPS for an upland load is slow, 40 MPH for a grouse is fast, so this is a conservative calculation. I just don’t see the grouse ‘flying into’ the shot string when it moves less than 6” from first pellet to last.

In contrast, with a 10 MPH crosswind a #5 lead shot pellet launched at 1,395 FPS will drift 10.6” at 50 yards, 15.4” at 60 yards. Double that for 20 MPH. It’s entirely possible a decent crosswind can drifts the pattern by well over 2 feet. In addition, drift is *probably* worse on distorted (less aerodynamic) pellets, blowing up the pattern even more.

Agree with the exception in this case we have two separate targets approximately separated by 8 feet. And the string is at least that long “far” out.

Their separation is what makes the difference. One got hit with the front and at practically the same time the one
behind got hit with the back portion of the string.

They did fall at almost the same instant. The time lag between the front and back of the string is very small. However, since the Birds were separated by the approximate length of the string, one got hit by the front and the other the back.

The length of the string and the separation of the targets have nothing to do with each other. Your assertion is the front of a 9 foot string can strike the front bird and the back of a 9 foot string can strike the back bird, assuming the birds are 9 feet (or less) apart, For this to be true, the shot would have to be traveling at the same speed as the grouse.

He hit both grouse because a) his pattern was large because of the distance, b) it was further enlarged and blown by the wind, and c) he likely hit the front bird with one edge of the pattern and the back bird with the other edge. It isn’t beyond reason to have a 6-8’ pattern at distance, bigger with some wind.

Well the shot is traveling faster than the Birds which makes my reason even more accurate.

In addition it is the same reason one doesn’t lead the front Goose enough and kills the one behind it. In this case he lead them both enough.

Did a strong wind have some effect in the pattern? Most likely.

I’ve seen the same scenario on separated clay targets many times.

This ^^^...

No, it makes your reasoning less accurate. As explained above, a grouse at full speed 90 degrees to the shot travels less than 6” from the first to last pellet arrival given a 9” shot string. If you think a grouse is running into the tail of a shot string while moving about the width of a human hand is a bigger factor than 2+feet of wind drift plus pattern spread....

The myth of the long shot string...Field and Stream

Thanks for all the replies... Interesting stuff!!

And I agree with both of those submissions....The difference is they are not referencing two different targets, relatively close and on the same plane....

In addition 8 feet of length was with the good non-lead shells....Add lead shot to the equation and the string becomes longer....

Now a short string will always put more shot on the target, which is good, and at the same time diminish the the chance of the above happening.

An example from Bristers "Shotgunning, the Art and Science" that demonstrates the exact situation that WCH experienced....




Brister again:

Just plain old math...

If a shot pattern is 25 ft long, but moving at 1,100 fps, it fully crosses the birds (a single point). In .02 to .03 seconds.

A grouse flying full speed or 20 mph, is moving at 29 feet per second... but .03 seconds = .87 feet = 10.5 “...


So 10” of difference = the max contribution of the shot column... the rest is simply bad choke / loose pellets.

Well you have to plug the right numbers in to get the right numbers out...

Because at 40 yards, for the shot size I could find, which was 7.5's...A shell at 1250fps at the muzzle is only going 636fps at 40yards...and the Birds stays in the shot stream longer...Your 1100FPS is an input error....

And your calculations are based on a 90 degree crosser...Add in some quartering to the Birds, and again they stay in the stream longer....and the numbers change again....

And the math becomes not so plain....

So a 20’ shot string at 636 FPS fully passes a single point in 0.03144 seconds. A 20 MPH bird moves 0.9 feet in that time. You are wrong about quartering shots. Traveling at 90 degrees allows the bird to move farther toward the back of the string than a quartering bird. A bird quartering away (or toward) at 45 degrees at 20 MPH only travels toward the string 0.67 feet.

If the string is 20’ and moving at only 636 FPS and the bird is 90 degrees at 20 MPH, the shot string ‘effect’ effectively adds 1 foot in diameter to the pattern. This is on a 4+ foot shot pattern, you are effectively adding 6” to each edge. Most of what I can find suggests the string is half that (10 feet) which is equivalent to adding 3” on each side of the pattern. Not much.

Most of the ‘shot string’ myths have been debunked with high speed photography and basic math. As always, feel free to draw your own conclusions.

Basic debunking of shot string

Nicely saying Brister was wrong

Wind is way more important than string

K1500
Take the quartering Bird to the extreme and make it a straight away..at which time it will be chewed up by the entire string. Therefore the more a target is quartering and approaching straight the more shot it encounters.

Your quoted article deals almost exclusively with which choke has the longest string and how it effects pattern percentages. Pattern percentages are two dimensional. Shotstrings are three and if you factor in time four.

The you tube video posted mentioned high speed shotstrings videos of at least 8 feet with the best shot. And longer with the worst.


You may want to discredit Brister, but do me a favor and find another knowledgeable shotgun ballistic expert that agrees with you. Admittedly today, shells are more efficient- shorter string- than when Brister did his work. However, I’ve yet see any that say his conclusions were wrong.

I don’t ‘want’ to discredit Brister, and your argument about a straight away bird again misses your own point. Your assertion is a bird can ‘run into’ the tail end of a shot string. That is, the first pellets missed the bird because they were in front of the bird and the bird flew into the tail end of the string. How does a straight away bird run into pellets that missed it? You do realize the tail end of the string follows the same path and the head of the string, right? The only way a bird can run into the tail end of a string is for the bird to be crossing. In any event, how about Phil Bourjaily?

Phil

You are missing my point in that a straight away misses essentially none of the shot. Front, middle, back. It gets chewed up by all of them. Therefore, again as a target goes more quartering and approaches straight away, the more shot it encounters. It has to do with the time dimension, in that the target is spending more time in the string. Or if one prefers a different term, the shot cloud.

I did mention Phil, and the fact with modern photography he indicated shotstrings of 8 feet at best and up to 15 at worst. And again he was talking about one target and not two flying in the same plane..WCH’s situation is specifically about two flying one behind the other, which means that 8 to 15 feet can be a factor.