Right now the only round I have seen hit 12 plus inches (12.5 inches of penetration) is a solid copper round in a non fnh ammo. Most of the rounds are in the 10 inch or less range when it comes to penetration. The solid round becomes even more of an issue since the tests I have seen show that it tends to not tumble, which is likely the primary reason it is able to penetrate as far as it does. Thats a problem since your dealing with a small caliber bullet and without tumbling it is effectively a pointy .22 mag bullet out of a handgun.
At the same bullet weight a .22mag will likely penetrate further given same barrel lengths. I am not sold on the idea of the 5.7 as a round that is in the league of the 9mm, 40, or .45. Primary reasons being:
1 The rounds that end up tumbling penetrate 8 to 9 inches in ballistics gel. I am not sold that tumbling is more effective then what a 9mm-.45 will do.
2 The rounds that don't tumble tend to be a straight hole, little to no cavitation, and still barely go above 12 inches of penetration. I don't even consider the FBIs standard of 12 inches the absolute minimum, however considering 9mm and .45 rounds designed for self defense can achieve 14.5 inches of penetration and .6 inch plus expanded diameter, the 5.7 leaves much to be desired.
3 People tout its armor defeating properties, however after going through a vest you would be lucky to see 6 to 8 inches of penetration. Its certainly no 5.56 round.
4 190 ammo is available, only if you want to pay huge prices. Most of the ammo around is expanding varmint type bullets, which do produce a nasty looking cavity in ballistics gel, however so does birdshot out of a shotgun.
So take your pick. You want a nasty wound and temporary cavity, pick the expanding bullets. Of course its at the expense of penetration (around 8 to 9 inches). Want more penetration? Then your going to limit the tumbling action and you essentially have a wound similar to a .22mag. None of the rounds penetrate in ballistics gel to what I have seen 147 grain 9mm or 230 grain 45 self defense ammo do.
I don't doubt that the 5.7 can kill, however I have yet to see any proof that it really offers anything better then 9mm, .40, or .45 acp does. Other then less recoil.