I have a wooden backstop
comprised of the remains of a VERY large Pine tree, that I lost in a storm (2+ feet in diameter at the base). There appears to be very little difference in penetration between the 3 different types, the FMJ and HP are almost identical, the SPs have some slight expansion and slightly less penetration. But this is a fairly "hard" target, not sure there'd be much difference at all in flesh, and suspect any of them will travel through multiple walls of a house (they penetrate about 5-6" into solid wood). Also, none are very accurate in either of my SKSs, nor my buddies AK. If you want reasonable accuracy, go with Winchester. I haven't checked penetration withe Winchester, as I've only shot it at the range (as opposed to my "home range"), but it is more accurate, and has a true hunting type bullet.