I just aquired a model 34-0 4" BBL. I did not clean it before I took it to the range. I was shooting different kinds of ammo. After a while, the hammer refused to go back into single action and the trigger would not release. This happened after 50 or so rounds. Happened 3 times. When I unloaded the gun and reloaded it, the problem resoled itself until it happened again after so many rounds. Could it be as simple as a dirty gun? Any advice appreciated. Other than this and an occasional difficulty with the cylinder sticking (ie ejector latch is loose, needs to be tightened) the gun was a tack driver.