I have a Remington 1100 16ga I keep under the bed, fully loaded. It's a semi-auto, so the action isn't the same. Plus it still has the wooden dowel in it (can't figure out how to get it out yet) so it only holds 2+1 rounds-no need to handicap myself.
But really, it's way too long for home defense. I'm not sure of the barrel length, but I'm guessing 24", so even getting it out from under the bed would be a chore. I'd love to pick up a 12ga Mossberg 500 with an 18.5" barrel for this purpose. Holds more rounds, shorter barrel, loud pump action. That'll probably be my next firearm purchase-as much as I'd love to have an AR or another pistol, a home defense shotty makes more sense.
Shooting birdshot from a short barreled, unchoked 12ga shotgun is almost gauranteed to hit an intruder even if you just fire towards the sound they're making. Plus the birdshot isn't going to overpenetrate any walls, or the intruder himself-so worrying about the best round with the most stopping power that wont OP walls or the target is a non-issue.