First off welcome to the forum, i'm sure you'll enjoy your time here. Now on to the problem with the double fires. I would check to make sure nothing is built up in the firing pin channel. I had it happen once with my PT-22 Poly, and noticed that the firing pin actually sits out of the hole slightly. If the slide just happens to hit with enough force on reset, the rimfire primer can receive just enough force to ignite and fire. Some primers are much softer than others and don't take a deep strike to let off a round. If cleaning the channel doesn't cure the problem, you'll want to contact Taurus about sending it in because there's possibly an issue with sear engagement that's allowing it to not reset with the trigger.