Discussion
Starter content written by the Rangium team to seed the community.
Don't forget ammo selection matters more than the caliber debate. A good defensive load in either platform behaves very differently from cheap FMJ for penetration. Choose deliberately.
PCC has real advantages: shared ammo, lower recoil, less blast, easier for everyone in the house to run. For a lot of people that's the practical winner.
Inside typical home distances both are devastatingly effective. Pick the one you and your household can run confidently under stress. Training beats caliber.
Counterintuitively, lightweight fragmenting 5.56 can penetrate interior walls LESS than 9mm pistol rounds because it tends to fragment and shed energy after impact. The over-penetration fear is somewhat backwards.
5.56 with a proper defensive load is my pick, but blast indoors without a can is brutal. If you go that route, plan for hearing protection staged with the gun.