So the lesson here is, make sure, that is, MAKE SURE you hit the bad guy, because if you don’t, the bullet is going to end up WAY past where you think it will end up. The question I’m left with, I wonder about birdshot as opposed to 00 Buckshot.
I wouldn't use birdshot, but you can use smaller buckshot and/or lighter powder loads (typically labeled "reduced recoil" or "tactical").
Yup. Training is key. IDPA is a wise choice.