Rob - how are you accounting for this when you teach the grip? Is a slight push-pull or compression (using the chest) recommended? It doesn't appear from what you show in your video that the support hand is getting anywhere near the backstrap of the gun so friction must be the means by which recoil is transmitted to the support hand.
ER,
Off the top of my head, my response is that you are thinking about the grip way too much.
Defensive shooting needs to be as intuitive as possible, not overly mechanical.
The Instructor Development Answer that explains my, and the Combat Focus Shooting, approach to teaching grip is to take the concept I just stated and apply it this way:
Tell the students that they need to hold the gun as high as they can without interfering with the action of the gun (the slide moving backwards), keep their finger off the trigger and not cross their thumbs in any way. This will get 90% of the students holding the gun "properly" without having to over think it. If they do need step by step instructions, use these:
1. Have the student hold the gun as high as possible in the strong hand (no gap below beavertail/above web of hand.
2. Place the trigger finger straight forward along frame while wrapping the rest of the strong hand fingers around gun, ensure there is no gap above the middle finger below the trigger guard.
3. Raise the strong hand thumb to create a gap on the weak side of the grip.
4. Use the meat of the weak hand at the base of the palm to fill that gap, wrap the fingers of the weak hand parallel with and around the fingers of the strong hand, ensure there is no gap above the weak index finger under the trigger guard.
5. Lower the strong thumb down so that the thumbs are layered and ensure that there is no gap at the back of the grip between the hands.
I hope that answers the question.
-RJP
