I joined the S&W club and bought a really nice condition 19-4 4" barrel deeeeeply blued beauty today. Now I just have to wait 10 days! I was doing the checkout on the gun and I noticed that when I pulled the hammer back it would occasionally not click twice on one of the cylinders. I'd hear the first click, but not the second click. This is only on one of the cylinders and only some of the time. Is this dangerous? Whats the best way to fix this for the least expense?