I think it is important to realize that the cylinder stop has to engage the face of the cylinder some distance before the notch in the cylinder. Not only does it have to engage before the notch, but it needs a decent amount of spring tension forcing it against the cylinder. That arrangement will necessarily cause some kind of turn ring.
If this were not the case, and the revolver is cycled very quickly (as in fast double-action shooting), the cylinder will "throw by" because the stop did not have time to fully engage the notch, or the spring was too weak to force it into the notch. That might cause the gun not to fire and to skip over a perfectly good cartridge. Or worse, the gun might fire, but with the cylinder slightly misaligned with the forcing cone!
Even if the stop engages with the notch enough to stop the cylinder, you still want the stop to engage deeply enough into the notch if you are doing fast, double action shooting. Otherwise, the quickly rotating cylinder will slam against the partially engaged stop, and the edges of the cylinder notch will eventually be peened.
I would much rather have a slight turn line and a gun that works perfectly, than a gun with peened cylinder notches or a gun that can't be trusted to fire quickly.
Colt revolvers tend to drop the stop pretty late in the process. And sure enough, you get less of a turn ring, but it is not difficult to get them to "throw by" with a very fast DA trigger pull.
If the turn line really bugs you but you still want to shoot the gun, you can avoid some of the ring by not rotating the cylinder by hand after closing it. Rotating by hand drags the stop against the cylinder until it finds a notch. Instead, align the cylinder so that the stop falls into the notch as you close it. Or close the cylinder and then, without manually rotating the cylinder, cock the hammer, which will lower the stop away from the cylinder face until it drops onto the cylinder in the normal place. However, you will still eventually get something of a ring just before the notch, since the mechanism must drop the stop before the notch if the action is cycled.
I suppose you could also partially draw back the hammer to retract the stop, then manually rotate the cylinder into alignment with the forcing cone, and then complete the cocking of the hammer with the stop cycling and then dropping directly into the notch. That would completely eliminate a turn line, but you would still get assorted wear marks in other places from shooting the gun.
Frankly, I like to see normal looking turn lines. That's honest wear for a shooting gun. If I didn't want a turn line, I wouldn't shoot the gun in the first place.
