@Red Leg - I saw your post of your shotgun being choked tight and tighter. I was wondering what distances are these being shot at? From the video they don't look close.
They aren't.
With box birds, the shooter is staring at seven to ten boxes or traps across his front. That makes them farther away as they launch to either end of that line. The nearest box is typically 33 yards and the farther two as much as forty. In the States, the boxes are usually spring loaded to toss the bird into the air. Each time in the ring, the shooter will normally get five birds. Each bird is launched when the gun calls for it. The gun will say "ready," the trapper will respond "ready," and the next noise from the shooter will launch a bird. The shooter does not know which box the trapper will activate. Obviously, keeping track of empty traps is a key technique for picking up birds. Normal matches are 25 birds, occasionally 30. The ring is typically 50 meters in diameter and is surrounded by a chain length fence twenty-inches in height.
To score the bird must fall into the ring. Should he fall wounded and mange to takeoff and get out of the ring it is lost. Only doubles or OUs are used and both shots must be fired (for safety reasons as much as anything). Shells are limited to 2 3/4 inches and 1 1/4 ounces of shot. Shot size typically cannot exceed #7. Most shooters use both on the bird regardless how well hit with the first barrel because of the wounded bird rule. Whenever the shooter scores five in a row (that can be a combination of two five-bird flights) he must move back a yard. Competitors shoot from a mounted gun position. You can do the math on range to target in order to shoot a perfect score, which unlike skeet and trap is pretty rare.
Typical guns are very tightly choked. With 7 1/2 shot, my purpose built 32" Cashmore shoots 75% right barrel and nearly 90% with the left. Remember a stone dead bird one-inch beyond the fence is lost, and a large hard driving bird like a pigeon can be difficult to stop in its tracks.
At large matches, lots of money is wagered.
The other form of pigeon shooting is called "Columbaire." Though both games use live pigeons, they are about as different as trap is from sporting clays.
In a Columbaire match, the bird is tossed into the air by a live human being to the shooter's front.
The ring is typically twice the size of a box bird ring. Four ten-foot poles connected by white rope at the top mark a thirty-foot square. The columbaire, or thrower, moves to a throwing position within the square and says "listo" or "ready." The gun takes up a firing position and says "pull" or something equivalent. The thrower then attempts to throw the bird in such a way as to be very difficult to hit. He may remove feathers to cause more erratic flight. The shooter can only fire at birds above the white ropes. Anything below is considered "no bird." Some of these throwers have the arm of Nolan Ryan and the scheming mind of Machiavelli.
As you might imagine, Columbaire takes a different gun. 28-30" are typical with improved modified or mod for the first barrel, and improved modified or full for the second. I typically use a 30" M/F AYA OU for Columbaire.
Needless to say, Columbaire is not a sport for an inexperienced shooter.
@camlo please fill in what I left out.