With clay's passing, I must slap the trigger after passing the bird 10" to 12" = poof!.
With a caplock or modern gun, I slap the trigger when the muzzle 'touches' the bird = poof.
That is with a 1,000fps load of shot, not 1,600fps or more round ball from a rifle.
More equating to do - or practice at that game will work.
Static holding (holding the rifle steady) and trying to shoot at something moving to your sights, is totally different.