JOHN BIDWELL says:
I will bet a fiver here that you are addressing the muzzles to the tops of the trees in front, then looking into daylight in the middle of the ride for your first sight of the bird.
All this means is that by the time you see it, the bird has got passed your gun and probably disappeared before you get the barrels moving. In short, you’re not catching up with them in time.
To regain the advantage, try this: Hold the muzzles not quite vertically and now look into the space between the barrels and the tree tops in front.
As soon as a bird appears, move the gun so that it is either in front when the stock hits the shoulder and the shot is fired or, you are able to pull ahead of it before it crosses the ride.
The important thing is that a bird like this should not be allowed to get in front of the barrel. To help ensure this doesn’t happen you can create extra swing when the gun passes the vertical by transferring weight to the back foot. All you have to do is get the courage to go for it!