It COULD BE a very common problem with new owners of Ruger DA revolvers - short stroking the trigger. If the trigger is not allowed to reset ALL the way forward the action will lock as you described. Most other brands allow you a little bit of slop regarding less than full reset but not Ruger. Your finger has to come all the way forward until it almost hits the trigger guard. My wife went through this during her "learning period" with her new GP 100. I have seen quite a few other people experience this problem. Don't blame the gun until you have positively eliminated the possibility of not allowing the trigger to reset. Like I said, this is a very common complaint, especially if the gun has been re-sprung with lighter springs. If a light spring kit is installed with a lighter than stock trigger return spring it can slow down the trigger reset enough that it seems like you're having to "wait for it" - because you are. This is precisely why Jerry Miculek uses stock or stronger springs in his revolvers. He is more than willing to put up with a higher pull weight if it allows him to cycle the gun faster - and it does.