Funny, on crossing targets I cut my lead back to keep from shooting in front of the bird. I rarely shoot behind and more often shoot in front. But I have shot a lot of .410 and do not find the lighter gun weight to be a problem. I shoot them aggressively and try to not only get my target line figured out in advance but also exactly where I am going to shoot the bird. Sometimes people think I am too fast but I find riding a bird with a .410 to be very likely to end up in misses. Short swings, quick and decisive shoots works best for me. Do not over think it, do not measure your leads. Be more Churchill type instinctive shooting style, but not so much a true swing through shooter. When the sight picture looks right just pull the trigger instead of checking, verifying and making it too complicated. You most likely will find the slower velocity shells will give you tighter patterns, but the faster one give you more smoke. Have fun, .410's are a blast.