Johnny is entertaining, but not for shooting advise. What I think he is trying to get across is that you can not focus on the fact you are shooting a .410, but instead you need to just focus on the bird instead. When I shoot a .410 I shoot it more aggressively than the 12. You do not ride birds across the field, you do not measure birds with a precision of a ruler. You get right after the bird, find the line, get your sight picture and shoot them. Trying to be too precise, with a .410, will lead to stopped guns and all other types of blunders. Find the line, determine if it is closing or tailing away, curling or falling as it runs out of steam. Those type of decisions.
On leads I do shorten them slightly, but my gun is active and moving. You may have a 30" wide, 12 gauge pattern, but that shrinks to 20-24" with a .410. So crossing leads need to be less the way I shoot. If I shot swing through, then I would not need to alter my leads, I might need to alter my gun speed, but on crossing shots I shoot more sustained lead and do need to reduce leads slightly. In narrow window shot, in woods, you can almost hold a dead gun and ambush the target as it enters the opening. Sporting Clays do give you the advantage of knowing where the bird will approximately fly, so take advantage of that when ever you can.
