MrTuffPaws said:
It is good habit to bend the first knuckle of your strong hand tumb when using a revolver.
That was part of my standard grip with revolvers until I bought my 340PD. The first time I fired it at the range, the cylinder release tore a BIG chunk out of the top knuckle, and it bled pretty badly. After slapping on a bandaid, I unloaded the revolver and went about figuring out how to hold onto the thing. This is what I came up with.
First off, I have slightly smaller than medium sized hands. If it matters, I'm one of those people who have always had trouble holding onto Glocks, but found the XD-9 to be a pretty good fit. Anyway, I hold the revolver high on the grip. The webbing of my strong hand comes about even with the top of hte rubber grip. Your 642 has the same grip as my 340PD. I let my trigger finger fall where it wants to on the trigger (when I'm ready to shoot!), and learn to pull from that position. (I know people will say to pull with the pad of the finger. Well, I can do that with a SA semi-auto, but not a DA revolver with a heavy pull.) I press down on the rubber grip with the inside of my thumb joint. The tip of my thumb is actually hanging out in the air. It may feel weird at first, but you can actually get a good grip on the revolver that way, and it guarantees that the thumb knuckle is out of the way of the cylinder release, and it also allows the trigger finger to pull through without hitting the thumb. The weak hand is cupped with all five fingers together, then placed over the strong hand so that the notch between the tip of the thumb and the side of the index finger meets with the base of the trigger guard. The weak hand thumb presses down onto the topside of the strong hand middle finger. Pressure is exerted forward toward the target with the strong hand and backward towards the shooter with the weak hand. The grip on the revolver with the strong hand medium.
Which ever method you do adopt, I recommend you stick with it, and don't use other grips with similar revolvers you may purchase in the future. I also own a Taurus 85, a Taurus 850 and a Ruger SP101 357 3". All of them are steel, and I used to shoot all of them with a thumb curled down position. I now fire all of them in the same method as my 340PD, in order to maintain the muscle memory for the 340PD which is my primary carry piece.