Taking it apart and looking over everything is a good idea. It's a very simple mechanism, unlike a lot of revolvers and is very easy to figure out. Only one of my 15-2's was rough inside, the hammer had some burrs on it and a little stone work, and a whole lot of dry firing, enough to get my mother to yell, "Stop that!" and then a little cleaning inside and some teflon lube, and more dry firing made it the best of all my DW's. The 15-2 I have now is pretty close, and the 715 isn't far behind it.