I also only take "in the air" shots. If you need the meat as previously stated, hunt a larger game maybe.

I took my step-son duck hunting for his first time 3 years ago. We had a single goose come in. Perfect chance for the boy. He did not have his pump gun closed all of the way and the gun would not fire. I quickly (but safely) exchanged guns with him but by that time the goose had landed. I wanted to see him get the goose to help keep his interest so I (hesitantly) told him to go ahead and take it. After 3 shots, which all patterned well around the goose, it flew away aparently with little or no trauma. This proved to me that you shouold shoot 'em in the air. The feathers are just too thick to penetrate when folded up.

Good luck with the Duck!