Mounting the gun
Make the first move with your front hand (a), starting the muzzle in the direction of the target. Sweep the muzzle toward the target and start raising the stock with your trigger hand (b). Instead of mounting, then swinging the gun, make the swing and mount one motion. You want your eyes on the dove. Lock your eyes on the target, keep your head still, and bring the stock to your face (c), not to your shoulder
Making the shot
Focus on the beak. As you move the gun to make the mount, keep the muzzle below the bird’s line of flight so the gun never obstructs your view of the dove. As long as your eyes are focused firmly on the target and your gun isn’t in the way, you’ll be able to see and react to the dove’s dips and jukes.
On long crossing shots, mount the gun ahead of the bird. Keep your eye on the dove, but insert the muzzle out in front. Match the bird’s speed, and trust your subconscious to find the right lead. Resist the temptation to look at the muzzle to measure lead. Remember, you’ve got a wide pattern spread to give you plenty of margin for error.