Those are what my Academy instructors called “self-correcting” mistakes.
CC
This is real, and you have to watch how you hold your revolver. It is worse when the cylinder/forcing cone gap is larger, but still a problem even with the closest tolerance. It is worse when you get larger in caliber.
If you’re thinking it’s BS, take a close look at the Circuit Judge Revolver Rifle. They had to put a guard on the cylinder/frame junction to keep users from getting their hands damaged when the user tried to hold the rifle back farther than recommended.
ARFCOM had a guy post a picture of his thumb, BLOWN OPEN TO THE BONE, after he put if forward of the cylinder of his .500 SW Magnum. Crazy stupid.
The thumb injury from a recoiling slide is bad but that may not be the worst part. It could also induce a failure to extract, stovepipe or failure to feed malfunction that would require you to clear the weapon before a follow-up shot. That might be the difference between life and death.
Aw. I thought he was gonna hold it sideways for us. You know, gangsta style.
Just the other day I shot 50 rounds though my 9mm Taurus semi-auto pistol, and held my left hand on the barrel to steady the gun. There was no problem of any kind, and even the person at the desk was impressed when I showed her the target pattern from my shooting.