In addition, the Mini-30 has a much louder muzzle blast in my experience, and it is hard to find reliable large capacity pre-ban magazines for it.
Moot point if he's in Kalifornia.
Really, the best would be a Saiga in .223. .223 with good bullets (OTMs, HPs, etc) fragments well in close range engagements, so it does a lot of damage, stopping the threat quickly and reducing overpenetration. Typical pistol rounds overpenetrate worse than a good .223.
Also if you move out of Kali, you can convert it to standard AK configuration fairly easily.
My second choice would be a Saiga in 7.62x39.
Third would be an SKS.
The 7.62x39 has three good defense/hunting rounds for it:
The best is the Cor-Bon DPX loaded rounds. Very expensive, but they do the trick, and you probably won't shoot a lot of them anyway.
Next would be the Hunting Shack rounds loaded with Hornady V-max bullets.
Last would be Wolf Military Classic 124-gr HP. It shows good fragmentation, giving good stopping, and reducing penetration.
The other advantage of of the Saiga and SKS is the military sights. Zero them at 100, and you can set them to various ranges just by sliding the rear sight to the correct elevation. Might not be dead on, but will be close enough.