Ours never backed out, but I put a drop of locktite on them when the problems first were reported. S&W should fix it pronto for you and at no cost as they should. Ours, as reported in another thread here, have been great guns. No problems and 100% reliability, and they feed JHP's just fine.
The laser is useless in my opinion; the button is just too far forward to reach when you'd realistically use it. That said the laser-less model is probably a better buy especially if it's cheaper.
When you get it back, I'll predict that you'll like the gun for its intended use.
Rod