I hesitate to suggest powder loads for others, but I use 16 - 17 grains of either RED or GREEN Dot, and still get my share of claybirds. It depends on how everything fits into your shell with a proper crimp. You might have to try several hulls before you find the right fit. If the column is too low, the solution is to drop one or more dried beans into the shot to bulk it up. If too high, try a different hull or drop the shot load a bit, assuming you went modest on the powder.