.308 for Home defense?
Depends on your situation, and how big your bad guys are. I hear they get pretty big in Louisiana swamps, like the gators.
If there is any place in the US that in theory should be gun friendly to a home invasion defense , law wise, it's the French law based state of Louisiana. YMMV, depending upon your local DA.
Without more details, can't say if it's a good choice.
Since most of us never have to use our HD guns, I'd give 99% consideration to getting something you can use for other things, and something you would enjoy shooting, and can afford to shoot a lot.
I really don't get all the naysayers about battle proven rifle rounds for home defense. If you know where they are going, like into the wild, or into a berm
or levy, then go for it. Be prepared for blast a bit like a concussion grenade.
I think that makes a GREAT home defense weapon, and, combined with the muzzle flash and burn, a devastating defense weapon.
I would be concerned that the ammo you pick cycles your semi auto. That means testing and shooting with that ammo.
Before I forget, some of the full weight soft points in .308 are pretty devastating, and don't penetrate much. You might not need varmit rounds, depending on where you live, and where your shots go if you miss.
Also keep in mind that your expensive rifle may end up destroyed in a police evidence locker if your local DA thinks you committed murder instead of home defense. They can't exactly oil your gun after a shooting. Destroys evidence.
I've got a Mosin Nagant M44 ready to go. Short, handy, and 7.62 X 54R is pretty much .308, or .30-06, but cheap.
Since most criminals are under the influence of something or other, the extra power the proven rounds provide is certainly a valid concern.
The problem with shotguns is you need a place to practice with them, and for me, that is nowhere around here.
I've always wondered how many times home invasions are foiled by the presence of a rifle vs. a handgun. I know I would be the LAST person that would want someone shooting at me with a .308, and I would be running as fast as I could the other way if someone had one pointed at me.
The above observations in war are from .308 NON-EXPANDING AMMUNITION, or should be. Using expanding ammunition the .308 would be even more effective.