I would feel very comfortable with a 10-22 with a 25-round clip or even a Mark 2 with 10 rounds.

I know everyone thinks they are great shots, but I am fairly good at shooting, I do a lot of it. I feel 10 22-rounds would stop a dog. The one time I did shoot a dog that came at me, I got it on the first (and only shot) in the head with a 22-250 fired from my hip as I was walking back to my van after woodchuck hunting. I was walking along a railroad track (magazine on the gun loaded with the bolt open) and the dog broke through the brush 20 feet away and growled and started for me, I stopped and backed away slow. It kept coming. I worked the bolt and fired from the hip.

I think I could stop a person with a 22 that broke into my home.