You hear a bump in the night and voices downstairs. It's a home invasion by more than one badguy. They are now coming up the stairs and you have only seconds...
Earlier in the evening you had placed one firearm next to your bed:
- A tested and true semi-auto pistol, any brand, any chambering, any load.
- A tested and true revolver, any brand, any chambering, any load.
- A $225 12-guage Mossberg Maverick Pump (7+1), any load. You ran a half a box of shells through it as a basic function check.
We can construct scenarios 'til the cows come home (where did room clearing come into the picture?) but the OP was pretty clear. Bad guys coming up the stairs, you're alerted and have had time to arm yourself.
In the military when in a defensive position, you use your wire, mines and other obstacles to funnel the enemy into your killing zones so your WMD can take them out. What the bad buys have done is funnel themselves right into your killing zone, giving you just about the perfect defensive advantage.
They're coming up the stairs so it's highly likely they're in single file. Unless you live in Rhett and Scarlet's mansion, they have a wall on one side and a bannister on the other, so they can only go forward, backward (difficult for anyone but the last in line) or over the bannister. You're alert, they don't know you're alert. You know your target will appear in about a 3-4 foot wide area. You live here and walk those stairs every day so you know where they are even if you had your eyes closed.
The first guy will appear before the others have cleared the top of the steps to be able to see you. As soon as the first guy's torso clears the top step - BOOM - he's now a slippery obstacle for the others. If you're a hard core sort, you exploded his head to add a little psy-ops effect to the next in line. The remaining bad guys can either go forward one at a time over that obstacle, still not knowing your exact position except that you're in front of them while you know exactly where they will be, or they can retreat. They can try to come forward two at a time but that's going to be difficult on the average home stairs, plus if they're shoulder to shoulder they don't have any room to maneuver at all. And they still have to step on or over the inert form of the first guy in line. If they come forward one at time, they instantly have two obstacles to walk over, then three, so on.
Unless there are more than eight, (7+1 in that Mossberg) they are basically committing suicide to continue to attack.
In this scenario basically any of the three choices would work, I'll still choose a shotgun since I don't want to see if I can acheive a "one shot stop" or try for a CNS hit with a handgun, especially in the dark - I want to f***ing blow the sh*t out of their heads and insides. I don't want to give them one teeny tiny chance to return fire, I want them DRT. I'll worry about the mess later, when I'm still alive and they aren't.
