I'm buying a 12 gauge Mossberg 500 next week for home defense. I've been looking around but can't seem to decide what type of ammunition would be best to use. I live in an apartment complex so I was looking for something that wouldn't penetrate the walls (birdshot?). I also read around that 00 buckshot was good but might be too much in an apartment. This will be my first gun and not really sure what would be best. Thanks!