Most people think that you are loosing a lot of fps with shorter barrels but this is really not a factor, as much as how the person swings or follows through with his shots on birds that that can mean 24" to even 5 feet !!
True weight of guns call for different swings and do swing different and one has to learn how to swing each type of gun that he owns. My A-5 is a lot different than my "Plastic" 391 or my long barrel ,win pump .410 vs my SxS 20 Ga 28".
A proper choke in short barrels will also make up for any differences, if your patterns are not up to snuff.
ANY gun will kill birds, IF the guy pulling the triger,does his or her part and this usually calls for..............
I will go to my trap club and shoot a full box of shells at just the #4 station or shoot just stations 1 & 5 at the trap range.
Look at where you want the pattern to go......................and not at that stupid front bead.