All types of guns can wound if the shot is not placed properly. However, in my PERSONAL experiences, I have seen far far more deer wounded by buckshot than any other firearm projectile (a lot of bad archery shots out there, string-jumping deer etc).
Someone mentioned a shot where they killed a deer at 65 yards one pellet in the back leg and one in the chest. That chest pellet could have just as easily gone through the stomach. With buckshot, there is always luck involved in the hit placement. I don't see why if you trust yourself to center the pattern over the deer accurately enough to ensure adequate pellet hits, you don't trust yourself just to put a slug through the center of the pattern and make a big hole.
If someone wants to limit their buckshot attempts to 25-30 yards, I have little problem with that as it usually means a lot of holes. However my first year hunting I had a side-by-side, so put buckshot in the full choke barrel. It patterned well. A doe stopped at 30 yards, and I fired the slug. She jumped, then stood still. I carefully aimed again and fired the buckshot. She ran and soon fell, the slug through her heart. Skinned her and found NO buckshot. Never touched it again.
It is commonly accepted that a .44 cap and ball revolver is inadequate as a primary weapon for deer. Yet the largest buckshot carries far less power per pellet than this. So I'd say stick with 00 or bigger if you are going to use it, and make darn sure your pattern is good.
Just my observations.
