"Keep in mind, I’m a lowly school teacher with all the buying power of a chihuahua right now...(but I still want to be able to tell an intruder, “Drop the chilupa!”
This is what the poster specified his needs were. I don't think he has rooms with 100 yds between walls, do you?
I am also aware that my 40 .cal is worthless at 100 yds, and I am also aware that my tactical shotgun is worthless at 100 yds, which is why I also own a scoped 30/30 and an AR-15.
A shotgun is NOT “worthless” at 100 yards, or even 200! It’s a death machine at 100, and will sure make somebody decide on another plan at 200.
At 100 yards, you’re going to put several out of nine 00 buck into a bad guy. Two or three .33 caliber balls at about 800FPS is no joke. One or two at 200 yards at 500FPS will ruin their day too. So keep shooting them! But heck, at 100 yards, a shotgun is deadly, and you WILL get the hits.
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.