I finally got time to watch the video link of Jerry. I had seen it before. And yes,, at around the 7 minute mark, he does mention a hard, heavy gripping method. However,, he's ALSO talking about competition, speed shooting, and using competition loads. His 625 he's using is set-up for his hands, using his competition ammo, (which makes major power factor,, but not by much,) and is mild ammo when compared to factory ammo.
For the folks not familiar with USPSA major or minor Power Factor,, it's as follows;
Bullet weight, multiplied by velocity, then divided by 1000. Example; .45 acp 230 grn bullet with a velocity of 725 fps will give a number of 166750. Divide that by 1000 & you get a PF of 166.75. You are required to get a minimum of 165 PF to be called major.
As you can see,, that load is below normal factory ammo for most .45 acp ammo.
And with such light loads,, it is much easier to control recoil than with heavier ammo or calibers.
Even later in the video,, Jerry mentions different gripping AND how recoil should be "straight up," so that it can come right back down for the follow-up shot(s). When he's mentioning shooting a J frame he discusses some of this. He also uses a different grip when shooting a 460 or a 500 S&W.
Now,, all that aside,, I've had the pleasure of Jerry's company several times. I met him, Kay, (his wife,) and their young daughter long ago. Long before Lena decided to get into shooting. I've been his RO at USPSA matches,, as well as having discussed many topics. For instance,, many people think his guns have lighter springs in the actions,, but not true normally. In fact,, often having heavier springs. But the action has been very well tuned. Jerry also has what I call "shorter & thicker" hands & fingers. My fingers are longer than his,, but his fingers are much thicker. And his hands carry the callouses of a hard working person. His arms are shorter,, but his arm muscles are solid.
In the video,, he discusses the nerve in the thumb area,, and how it can & will affect shooting. He mentions how his nerve is already dead due to his decades of shooting. It's the part about "bowlers thumb," and how a heavy recoiling handgun can & will let you know something isn't quite right. Fighting recoil can also affect that same nerve,,, causing damage.
So, yes,,in a small part of his video,, he does talk about hard gripping. But take the WHOLE story & study it. Watch him shoot heavy guns,, and see the recoil. he works WITH the physics of recoil,, and knows you can't fight it physically. Yes,, he can death grip a revolver,, shooting mild ammo, for speed,, with his hands & arm strength. But he also can't physically death grip a heavy recoiling handgun & keep it from recoiling.
Just ask him,, as I have done.
Kinda like the comment above; The differences between the little old lady vs a guy who bench presses 250 with ease. Hand each one a .22 & the little old lady will feel more recoil than the guy, but do just fine. But hand them each the .500 S&W the guy will feel the recoil, while the little old lady will likely not be able to even hang onto the gun.
My point is that a death grip is not the best method,, for most shooting. Yes,, if you are shooting for world class speed, in a competition, using mild ammo, then, yes,, it can work. Shooting a short barrelled, compact .357 magnum, with full power factory ammo,, not so much. Even Jerry says; "If you have all the time in the world,, you can do,,,!" In his case,, time was a big factor.