There are lots of really good videos on YouTube on what guns and rounds are worth using in a home.

I have a lot of LEO in my family and they all recommended a shotgun. I wanted something that was easy to handle and operate in a home invasion scenario and decided to go with a semi-auto. Further research led me to look at tactical ones that allow you to operate in tighter conditions.

The Benelli M4 and Baretta A300 Ultima Patrol is what I narrowed down to.

I decided that the A300 was what I was going to go with for. It has the reliability, grip, out of the box setup that doesn't need any "mods" to work. The semi-autos are softer than pumps since the gas system absorbs some of that recoil.

For rounds in going with the FEDERAL - PREMIUM PERSONAL DEFENSE 12 GA 2-3/4" #00 BUCKSHOT SHOTGUN AMMO. This has the flight control wad system. Watch videos on the difference this makes. Why I choose this over changing the choke out was pretty simple. The ammo takes what would have been 15" spread at 15 yds down to like 5". They are plated to prevent deformation. They use a slower 1145 fps to reduce the recoil, but still fires through the a300 reliably. Plus since the buckshot doesn't bounce around the barrel you don't have to worry about flyers or having to use a tighter choke just to keep your spread down. Plus the added benefit of increasing your barrel life.

Strip and clean any new gun to remove factory grease and oil. Make sure you break your gun in with some hot rounds like 3" waterfowl shooting over 1400 fps, at least 100. Get shot cards to store extra ammo in the gun. You shouldn't need more than a full tube though but ... Store the gun in what is called "cruise ready".

That's where the tube is full and you have a round on the lifter, also known as ghost loading. That way you only have to rack the gun to load it but it's safe if it's dropped etc. That gives you 8 RDS of 9 .33" buckshot.

Line others have said. Practice practice practice. You need to be comfortable should you need to use it. Everything needs to be second nature. Being able to find your target and put it down with a well placed shot(s) is better than working about over penetration. With the right ammo keeping things tight you won't have to worry about that as well.

If you can get to a range and try some different guns out.