I'll say it again. Go shoot some pigeons!!! It sounds like your setup is fine. Unless your perception of 30 yards is actually 80, the only reason I can see for only dropping 1 duck with 2 boxes is your aim is off. Don't mean to sound harsh. Just sounds like you're worrying about things that aren't to blame. I just shot 2 rounds of skeet this afternoon with my friend because he's been struggling with his shot the past week and he's been shooting the same setup for 15 years. We all need practice. He figured out what he was doing wrong though and is ready to start whacking birds again. I on the other hand shot a great first round and then stunk up the place with my second so tomorrow's hunt will probably suck for me.