I really think the bottum line is that, reguardless of what your are loading/shooting, the most important think is to know the capabilities of your choosen weapon and rounds, and your abilities with those two. I mean, whatever you decide to load up, know where it is gonna hit at, and how far away you can effectively expect to shoot in reguards to your desired result. You could have whatever you think is the biggest baddest weapon, with whatever you think are the biggest baddest rounds, but if you are not familiar with the weapon, or the rounds or how the two interact together, you are doing yourself a grave injustice. Not giving yourself a PACE is also an injustice. Have you practiced how you would clear your house? What would be the best method? Ya, you may live in the house, and be familiar with the layout of it, but that does not give you as much advantage as if you have thought about it, gone through it, and rehersed it. PACE= Primary Alternate Contingency Emergency.
For instance, my PACE for WOC
P= 870 shotgun 12ga
A= H&K P2000 .40
C= 10/22 .22
E= Pepper spray and a collapsable baton
Practicing with your WOC is also extremely important. I used to have a golf club as my emergency, but by practice, I learned that if was really not effective as I could not really get much swing indoors.
My PACE for my MOC is quite extensive and would not be understood unless you knew the lay of my place. But my Emergency plan does include going out a window and coming back in a door. Have a friend come over and you two war game it all day long, him being a burglar, how he would move through the house, what he would do, where he would go, how you would counter it etc etc etc. You would be surprised what you will learn.
I mentioned what I load earlier, a .00 slug alternating combo. I know for a fact that it will go through walls, and believe me, if I deem it nessessary, I will shoot through the walls. I would rather patch drywall, then be put in a bag. As far as killing vs wounding/incapacitating, I would rather be judged by 12 then carried by 6. Know your state laws as well. The law for the state I am currently stationed in states that I have to tell a burgler/perp to stop and that I have a weapon, and "ask" them to leave....... 3 times!!!! Dead men tell no tails. As far I am concerned, I did ask 3 times. He is in a bag, he wont argue with me.
In reguards to your choice or #7 vs anything else, what would you NOT want to be shot at with? I personally would much rather you shooting at me with bird shot then .00 or slugs. .00 and slugs are the rounds I would least want to be up against, thats why I load them.
The afforementioned is all my personal opinion. What works for me may not work for you. Take it or leave it.