Muzzle alignment versus traditional iron sight alignment
This piggybacks off the SWYNTS.
Traditional iron shooting requires meticulous head and eye alignment with the sights.
Dot shooting if parallax free allows more freedom in head position and use of peripheral vision and still keep muzzle on target.
This is something that @HCM has noticed with training shooters that dots excel in moving targets and movements. Likely due to additional freedom of alignment while still keeping muzzle on target.
When I shoot, I’m keenly aware of my muzzle index independent of my sight picture.
That’s why a press out rather than a casting draw. That’s why I train index independent of visual correction.
That’s why I notice a distinct difference when I change to a different gun with a different NPOA like a 1911 or Glock (and why I modified mine to match CZ / Sig angle).
In traditional teaching based off irons, I feel like iron sight alignment has usurped muzzle alignment… but iron sight alignment introduces additional constraints that muzzle alignment does not.
That is, you can have muzzle alignment without sight alignment.
Index is the basis of uncorrected vision shooting, but doesn’t get the attention and specific training that it deserves IMO.
This is the greatest source of plateau of efficiency and marksmanship in a dynamic setting (also IMO).
This came about in helping people make time at the 3 yard SWYNTS (0.8 draw, 0.2 split).
https://youtu.be/MNL6xqIbmDo
And a demonstration of base mechanics that vision and visual correction / refinement builds on.
https://youtu.be/ZFu0QDcakjE
Think about other kinetic sports
In golf, do you look at your golf club when you swing?
In baseball, do you look at your bat?
In tennis, do you look at your racquet?
I'm not an expert in those sports...
But I'm assuming no. In golf where there is a high level of precision, you look at the target (which is the ball after you set up your alignment).
In baseball and tennis which are more dynamic, I assume you don't look at your bat or racquet... but track the travel of the ball plus dart eyes to where you want it to go.
Do you look at your gun in the holster as you get a firing grip? Or do you count on your hands to tell you the information?
Same thing with index. It just gets more and more refined if you work on it.
And doesn't if you don't.
Here's a physiology example.
As people age, their proprioception diminishes. But they often don't notice because they compensate with vision.
But what happens if it's dark, they close their eyes or otherwise lose visual input.
The answer is akin to field sobriety testing. You wouldn't know they're impaired without removing the vision, but it absolutely reduces their ability to react and coordinate.
It seems to me that if you were gunfighting (as a non-gunfighter), you wouldn't want to neglect the proprioceptive training. Because eyeballs are squishy.
And proprioception / index is actually the core of efficient gun mechanics, not vision.
Here were some blind reloads I did a few years back as a demonstration.
https://youtu.be/OrrZRE4Ffzk
You can see my core proprioception wobble (also seen in my closed eyes draw video). It's not a very refined system, so I prefer to use my eyes to micro adjust and speed up while improving accuracy.
But people who primarily use vision without developing proprioception will always be slow and inefficient because they're requiring external cues and feedback loops to get where they need to go.
This is an example of someone who lost his proprioception:
https://youtu.be/pMEROPOK6v8
He has to look where his body is. Most firearms shooters are like that. They don't know where the muzzle is pointed unless they look.
I would wager a good part of the "automaticity" that @John Hearne lists in his chart of the spectrum of shooter skill can be broken down into creating proprioceptive extension of the muzzle to your hand (the index).
But most people and instructors don't specifically train that way.
It'd be like if a baseball instructor insisted you keep looking at your bat instead of working to gain core index off proprioception independent of vision. Sure, some people gain this incidentally with a high volume of contact. But not as rapidly as people who train specifically for this.
This is where competition shooting comes into play. The core of higher level competition shooting is the proprioception skill. It's clearly apparent in watching match videos who relies on visual feedback to get in the ballpark (slow and lots of macro corrections based off vision) versus someone with a good core index.