User blog comment:Brothertim/FMJ in SMG: tips?/@comment-1079585-20100519153742

The UMP seems to have medium penetration (snipers, ARs, LMGs, and high-caliber pistols), and I think the rest have small penetration. But yeah, Hardcore makes it way easier, and you should be camping while you do this anyway. Also, keep in mind that killing people through grates or unbreakable glass is a very easy way to get wall penetration kills. Note that killing someone through a chain link fence does not count as a penetration kill.