[QUOTE=scooter123;136400626]Is this failure to reset in double action allowing the cylinder to rotate on the next trigger pull but NOT cocking the hammer? If so, you need to chamfer the tip of the DA Sear on the hammer a bit more. It's part of the process of fitting a new hammer assembly and may have been skipped by whoever was "smithing" on your gun before you acquired it. Attached is a pic of the chamfer and angle on the hammer assembly that was installed in my 625 JM, so it's an untouched factory part.

This is called the "short cut" on the sear by S&W.

Hope this helps
chris