Unless you are shooting rifled slugs, in which case, your range is extended a bit (150 to 200 yds max). Even at that range, a 1 oz, .72" diameter piece of lead is going to HURT.
The thing is that around here, the only range does not allow the firing of anything other than birdshot. No buckshot, no magnum rounds also cannot fire into paper targets on any of the ranges, only at clay pigeons or into the ground.
So I have not been able to test the spread pattern for buckshot out of the 18” barrel in any way. I would either have to find some far away woods and fire it there or take it to an out of state range, such as in Louisiana.