Shotguns are actually crazy accurate. When I took the combat shotgun course a couple years ago, we shot buckshot from 30 yards away and the group the pellets made was still pretty tight, like within an 8 inch circle. I was seriously impressed. The instructor also taught us how to make slugs out of buckshot shells, but said to only do it in a combat situation as a last resort if you really needed them. That course was fucking awesome.