My recommendation? Don't use buckshot. I know its tradtion in many places, but a great many people simply don't really know how poorly it performs. If you insist on using the buckshot, pattern it. Use whatever shoots tightest. the problem is this: Many people might try shooting a round or two at 15 or 20 yards, but few ever pattern the stuff at 40,45,50 yards. at those ranges a lot of shotguns are miserable, and instead of a half a dozen pellets in the vital area, you've got one or two in the lungs, a third in a shoulder and another somewhere in the guts. No one would advise hunting deer with a .32 ACP pistol but compare energy, velocity and bullet diameter. The average 00 buck is basically a 32 ACP performance wise. And 00 buck works when you can get 5 or 6 of them into the vitals. Thats really difficult with many shotguns. And most guys won't pass up a 50 yard shot on a 12 pointer if the shotgun is loaded with buck. That usually means a poorly hit wounded deer.
Use a simple foster slug in whatever gun shoots it best. call it good. The slugs work soooo much better than buckshot