I use a similar method to Frank,

When I get into a flock of grouse during hunting in the fall, after you shoot the first one the rest are usually spooked and scatter a little. I move up to the one on the ground, wring it's neck so it does not get away and continue to put the moves on the others.

I have shot my limit from one flock doing this, it is easier to do with a .22 using sub-sonics because it is quiet.

Mike