I have a pair of .38's with the black grips. Had to have the hammer springs lightened up. The timing on the one is PERFECT (and better than all FOUR of our Rugers). The other one is acceptable.
There is a bushing under the hammper that can loosen. If it does, you can fashion a tool to tighten it from an ordinary fork. Cut off the two outside prongs, see if the two inside prongs fit in the bushing and adjust the fork prongs by filing if necessary.
Our guns were $359 each. The one does lock the cylinder if you pull the hammer back too far when loading or unloading. I don't use this one for a reload on the stage. Otherwise, I'm thrilled about them.