Blasphemy, I know, but that wedge is not supposed to go all that far in. It is a consumable. It will distort, or get mashed during prolonged firing.
You should be able to smack it in with a 3 pound hand sledge and not close up the cylinder/barrel gap, IF the arbor is the right length. The arbor should bottom out in the arbor hole. Thumb pressure should be all that is needed to put the pistol back into shooting mode. It should also take no more than a light tap, I have read that them old guys tapped with a loaded replacement cylinder to loose it.
Regardless the patent description, though it may have been one of old Sam'l's ideas, it is to keep the wedge from falling out when you are ahorseback and changing cylinders. Imagine trying to hold onto the wedge, cylinder, barrel, frame and putting the new one in place. That with 2 hands.
Limiter, loose the screw on any of your Colt's and see if you can turn the screw a 1/4 turn and have it stay there. They did not use Nylok or other types of restrained screws. Spin freely. Supposed to be run home and simply keep the wedge from falling out.
As to the Captain's "lock up", I have argued this till I am blue in the face. IF you have a gap, with the base pin face butted, and drive the wedge in, AND close the gap, you are bending the arbor upwards, tilting the barrel upwards, raising the point of aim, shooting high. Many don't comprehend or agree with that. I wish I had a picture to demonstrate. I'll try to draw one and post my thought.
Cheers,
George