Having owned older Colt DAs & discussed them with Cunningham, Cylinder & Slide, and my longtime Colt-certified gunsmith, among others, I'll say that the old V-Spring action IS designed to drop the cylinder stop into the cylinder notch BEFORE the hammer reaches full cock when pulled back slowly.
If it doesn't, it's not timed correctly. It'll still function, but it's not timed correctly.
Also, WITH the TRIGGER pulled fully to the rear and the HAMMER down, there should be zero movement of the cylinder in any direction. That includes rotational and fore & aft.
If there is any movement with the trigger held fully back, it's not set up correctly. Period.
It'll still function, but it's not "right".
The action is designed to absolutely lock that cylinder in place at the moment of ignition.
Once either condition develops, it's an indicator that service is needed. It'll only get worse (typically the hand is shortening), and it's recommended that you get it corrected before it goes any further.
Many say "As long as it functions, I don't care", but it's the equivalent of saying "As long as my car still runs, I see no need to change the oil. Yeah, it's getting pretty black & sluggish, but the car still moves, so what the hey!".
Or, "My tire's bald, but it still holds air, so why worry about it?'
Or, "My temp gauge is pegged & steam's coming out from under the hood, but I'm still in motion, so why pull over now?"
Sooner or later, it'll catch up to you.
Those Colts were designed to meet certain specs, and the timing was important.
Very few gunsmiths today are capable of competently working on those guns, best is Colt for speed, if they still can. They're running out of parts & haven't ordered any new ones for quite a while.
The guns are obsolete & Colt can't be expected to service them forever.