Personally I cut all the scientific stuff out and light em up when there feet are down!Cleaner 1 shot kills,less frustration for your dog chasing crips,and few shootem again bs!!At 25 yards on your spread little to no lead,and less shy birds!Hunted 2 many public refuges to know 1700fps doesn't mean clean consistent kills at 45 to 60 yards!Letem work for more kills instead of how far we can stretch the gun barrel!just my take!!