I recently came across a youtube video of Israeli Jewish Marksman Sergey Richter, highlighting his unorthodox air rifle trigger technique. However, when I saw it, a light bulb went off for me. Here's the video:
Only Sergey can say exactly why he does it. But for me it seemed like an obvious way to "prime" the muscles of the trigger finger to operate independent of the rest of the hand, and thereby avoid disturbing the hold. Let me give some background. The standing position without a sling is the most unstable position in the shooting sports. That makes it the most challenging, most frustrating, and most fun. The body naturally moves, so you have a sense of a moving target. It is a lot harder to make the body perfectly still than most people would think. There are so many dynamics to successful standing shooting: good balance, extremely fine muscle control, and good reflexes. Depending on the weight of your gun, endurance as well. And don't forget chutzpah (you need it most in the standing position), and a bit of mazal never hurts. In High Power, for the standing stage the target is at 200 yards, with a 7" 10-ring (3.5MOA) and a 3"(1.5MOA) X-ring.
Broken down, there are two elements to successful standing shooting: your hold, and your triggering. Your hold is the natural path your muzzle takes as your body moves in position. Shooters practice making this path as small as possible. Beginners will have trouble keeping the muzzle within the 7 ring, top shooters can hold the 10 or X. Right now in NRA High Power my hold is mostly a 10 ring hold, at times an X-ring hold, and sometimes a sloppy 8.5 or 9. You don't need a perfect hold if you have good reflexes and can release a shot "on the move" as your muzzle first enters the 10-ring. Even if you have a great hold, on windy days you'll have to learn to shoot on the move as the wind blows your muzzle. On those days, you'll have literally fractions of a second to let off your shot in the 10, or miss your chance.
Triggering is the other half of the equation. You can have an X-ring hold, but if during the trigger pull your hand exerts unwanted direction on the rifle, you can end up with a 9 or worse. This is my major weakness at the moment, even though my trigger pull weight is only about 12oz. On the SCATT I see my 10's and X's turn into 9s and sometimes 8's because my triggering disturbed a 10-ring hold, or was not fast and aggressive enough. I have a really hard time activating only my trigger finger on the pull, and instead, almost reflexively, my other fingers move. (I have heard that this is normal for men, and women tend to be better shooters because their fingers are more inclined to work independently of each other, but it could be a shooter's wives' tale....). I can move my trigger independently of my other fingers, but it takes a lot of concentration, and in standing shooting you don't have that luxury--the triggering has to be pure reflex. I find myself not having the confidence to reflexively fire on a good sight picture because I'm not confident my hand is going to do the right thing. I feel like that is *the* hurdle I need to overcome to move up from Master to High Master.
What Segey's technique does for me when I do it, is that it helps my short-term "muscle memory" in my hand so that as much as possible, only my trigger finger is moving. It sort of points out to me any other muscular flaws in my grip so that I can adjust those too, as you do have to exert some force in the opposite direction for your trigger finger to be able to move straight back. I have a 2-stage trigger with a very long 1st stage pull, so it's perfect for this technique as I won't have to worry about accidentally touching off a round.
So far on the SCATT I've had tremendous improvement in both minimizing muzzle movement during triggering, and being more consistent with good trigger releases. I find the technique also lends itself to minimizing over-travel force as well. I've had 10 shot strings with more deep X's and 10's and my average is pushing up to 96, which is flirting with High Master territory. Hopefully it will translate to live fire, and maybe this is the key to me getting off my current plateau! I'm cautiously optimistic. Once again, I'm not sure this is why Sergey does it, but this is the effect it has for me. I could also imagine that it could just be a stepping-stone to triggering technique that does not need it, but I can't see how it could hurt even then.