TexasCHLforum.com

While I can't speak to it personally, I've read posts about and seen Ruger's notices about drop-fire issues with their SR9 and LCP lines.

And personally I had a Ruger Blackhawk that would fire if you tapped the hammer with any force at all over a loaded chamber. To give Ruger full credit though, they offer a "free safety conversion" to make them "drop safe".

http://www.ruger.com/safety/announcements.html" onclick="window.open(this.href);return false;

Hope this helps.