2 basic reasons I will not use a rifle for home defense. Over-penetration is the first. You can mitigate some of this with bullet selection.
The second reason is lead. Or more specifically, how much lead can you throw with each round.
I live in bear country. Have had one no more than 10 feet away, with nothing between him and I but air. Had them on my deck (pressing nose against window, staring at me eye to eye) eating out of the bird feeders, on my house, etc.
Having encountered these critters on numerous occasions, I admit that it does get the adrenalin pumping.
So, I use a 12 ga. for home defense. Don't worry much about over-penetration with one of these. This is for "home defense" I am not going to be shooting 100-300 yards down range. This is for inside the home, or maybe the distance of a "regular" yard.
In answer to the OP question, there is one in the chamber, and safety is off. I do not want there to be ANY question whether the firearm is going to work, because of having to rack a round into the chamber, when my adrenalin is on overload. Not going to try to scare the bear, with the sound of pumping a round into the chamber either.
Now considering a bear just broke into your house. You can fire 40-55-69 or 90 grain bullets at him, traveling at (+ or -) 3000 fps. Which is going to punch a little hole through him real fast, doing quite a bit of damage. Probably killing him, it's just that he doesn't know that he is dead yet.
(I know, multiple holes, and bullet selection)
Or you can throw 437.5
Grains of hollow point with EACH ROUND thrown at him, traveling at (+ or -) 1500 fps. LOTS of lead, moving a lot slower, tearing BIG chunks of brain and body parts off as it passes through.
Which sounds more effective in convincing the bear that he has LOST the battle RIGHT NOW
Oh, and if it is not a bear, but happens to be a critter that walks upright, talks, and eats sitting at a table, that has entered my abode uninvited, well....the same reasons/tactics holds true.
This isn't the big one that started to push his nose through the window, he broke the plastic storm window, but not the glass. This is just a small one looking at me through the window, after having destroyed a hummingbird feeder. Making a mess of the syrup, getting it all over himself and the window I might add.