I have a Taurus 441 that strated life as a 4" SB. I sent it to the Action Works in Arizona to have it cut down to a 3" and make it a RB. Love the way it shoots and looks. However, it has developed a problem lately that I cannot identify as to source. After I got it back from the Action Works, I had to send it to Taurus for an indexing wheel replacement. Now every once in a while it will not fire. The hammer comes all the way back and I am holding the trigger as far as it will go, but the hammer remains at full cock-then, bang, it will suddenly fire. Happened about 6 or 7 times in 70 rounds. Any ideas?