Just curious,But have you thought about Rifled slug's.
They were designed for the smoth bore of shotguns.
True it does not give you as much spin as a rifled barrel,
But they do a heck of a job on Deer,And have a longer range.
I myself DO NOT like buckshot,I've seen to many deer that
were just injured and not killed by it.
Yes if you have someone who know's the limit's of it and stay's within it's limit's,Then it might be alright.
But like I said over the year's I've seen Deer that were lamed up and not killed.
When I skinned them out after harvesting them I've found buckshot pellet's under the hide,Broken leg joint's
that have healed over with a Buckshot pellt laying right next to the re-fused joint.