You usually need a bit longer LOP with a double trigger gun than a single trigger gun. I find a gun with a longer LOP seems to work better for trap, while a shorter LOP works better on birds for me. What I'm wearing that day has an effect, also.
My first thought is to what the weather will be like, then I decide which canon to pull out. I freely admit, that this method does not produce automatic good results, either.

Best,
Ted