Our house is about 26'x40'.
Longest shot possible (Not in the basement) is 30'.
Go to shotgun is a 12 gauge.
It would take some effort, going to extremes, to find a load
that wouldn't be decisive.
Slugs are out, kick too much, penetrate too much, no advantages.
From 6's to 000, it's gonna work. From 1 oz to 2oz, it's gonna work.
Right now, 2 3/4" #4 Buck is the load. It has also been.
#4 or #5 3" Turkey loads.
It really wouldn't matter.
The AR is currently the gun to pick up though.
And again. At 30 feet, i dont think the load would matter much.
55gr FMJ to 90gr match it would all be good.
55gr Hornady soft point is what's loaded.