I apologize if I sound like a jerk because I misunderstand you but...

Are you saying you want to load with buckshot because you're going to be shooting at something when it is too dark to see well enough to shoot it with a slug? That sounds downright dangerous and irresponsible. That's how PEOPLE get shot. If you can't see it well enough to pick a spot and splat a slug into it, you shouldn't be shooting. PERIOD.

I'll sit on my hands about my overall opinion of buckshot as a hunting tool.