it will depend on the Buckshot size a full would be good with the smaller sizes like #3 Buck and a more open choke (Mod or Light Mod) would be best with 00 Buck the only real way to know is to pattern the loads with the different chokes as each gun choke shot combe perform differently

**Note** this is the reason just about every "self-defense" shotgun is Improved Cylinder. Modified compresses the buckshot just the right amount for medium to longer ranges for hunting. Full chock will usually cause more Buckshot deformation and "blow" longer range hunting shots.

The best chock is a Modified chock for mid to longer range. Improved cylinder for close up work.