Rossi M461/462 -- good, functional gun. Not the greatest DA, a little stiff, but they're accurate, reliable, and well built guns backed by a lifetime warranty. They sell for under 300 at Academy. The Rossi is the best cheap revolver on the market IMHO. That don't make it a Smith, but hey, it'll serve you just fine.
Taurus -- better gun -- MIGHT have to go used, but the M66 is a fantastic gun and used ones are WELL under 400 bucks down here. Also look at the Trackers. New ones, though, I don't know about that 400 dollar price point. Go up a hundred, maybe. Used is the way to go, big time good deals out there. I have a 3" 66 that is old, but tight and shoots fantastic that I got for $180. I carry that gun quite a bit, sweet shootin', very accurate.
Ruger -- you MIGHT find an SP101 for around 400. You WILL find new ones for 450, but they're five shooters. Why is a five shooter not acceptable? If you need six shots of .357, you either need practice or a wonder nine IMHO. IMHO, the Ruger SP101 is the best built of any of the revolvers I mention, best designed, strongest, and just one sweet gun for a great price.
Smith and Wesson -- in some parts of the country, you might be able to find a decent K frame for 400 bucks, like a M13 or something, but not down here. And, forget about a 3" model for that price, maybe a 2 1/2" one, but the 3" ones are rare and bring a premium for that. Good deals on Smiths are rare down here, though, and they're usually going to be pretty loose and beat up for 400. Me, I'll take a new SP101 over ANY used K frame any day of the week and twice on Sunday!