This is one of my biggest concerns with shotgun manufactures mostly for sporting, but also for target shooting at clays. I remember when sporting clays was in early stages and everyone was talking about the best barrel length being 28 inches.......where we all know where it went too. When it comes to clay targets........or live targets in my opinion. The LONGER the BETTER. YES it will make a huge difference!!!!! This is why certian people remain novice!!!!
Yes, longer for increased accuracy. And no, "no one" aims a shotgun but the muzzle or front bead is still involved in the creation of a sight picture, which gets involved when making the decision to fire.